996 Reliability Survey - Admin Approved!

Some time ago, Michael Karesh posted an attempt to gather real data on the reliability of the 996. A few immediately and incorrectly assumed that he was another disgruntled 996 owner that had suffered an IMS failure. As a result the thread and any good it could have done was blown apart. For those that don't know, Michael Karesh runs Truedelta - a site which collects real data on the reliability of various models of cars. I participate in his surveys by supplying him with repair info on my cars. Check out www.truedelta.com for yourself. It is the real deal. As we all know, people with problems tend to post while those without do not. What Michael is trying to do is to collect enough data to give us the real picture. This means that all of us who have or have owned a 996 without or IMPORTANT without problems are encouraged to report. If he gets enough responses, we'll get - finally a true picture of the reliability of the 996. I encourage all to participate in this survey. I am repeating Michael's original post below. ----------------------------- I wanted more up-to-date car reliability information that included actual repair rates. So in late 2005 I started getting people together to make this possible. TrueDelta now updates actual repair frequencies, not just dots, four times a year, to report on new models sooner then track cars closely as they age. With 350 owners signed up to participate so far, we've started providing reliability stats for the Boxster and Cayman. I would like to do the same for the 911. Just a matter of getting enough owners involved. So I'm grateful to this forum for giving me permission to post about the survey here. To encourage participation, participants receive full access to all results, not just those for the 911, for free. I'll share results, once we have them, in this thread after each update. For the details, and to sign up to help out: http://www.truedelta.com/reliability.php ---------------------------- Thanks for your co-operation!

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With respect, Bob, what Michael is trying to do is build a business. We might choose to call this 'collecting data for the common good' to make us feel better, but in my world we call it 'user generated content.' Speaking for myself only, i would have been more charitable if the request had been more transparent. Just wanted to be clear about my personal involvement in that debate.

Bob, we didn't assume he was disgruntled (at least I didn't) but rather identified once again the futility of this endeavor. I have spoken with him at great length offline so as not to bore the board with two statisticians talking shop. I do agree that the initiative he is taking is a good one in building a DESCRIPTIVE database. What we CANNOT do is be able to run any sort of credible analysis that would lead to a causal conclusion. There are many more aspects to this that need to be understood but I won't get into them here. As long as people understand that 1. This is a BUSINESS for him 2. This will be a repository of SELF-REPORT data from a NON-RANDOMLY SELECTED SAMPLE. 3. This data will have ZERO CAUSAL interpretation or value ps. if you would please Bob, please elaborate what "admin approved" means and why it is necessary. Is he a small business sponsor of Rennlist that has requested this be stated to earn some sort of "seal of approval"?

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+1.... and from what I see, from other forums (ahem, cough, cough BMW), the consensus is the same.... the more people sign up on his sight, the more money is generated for his business.

Thank you for posting this thread, Bob, it has been more effective than I expected. 200 owners have signed up for the 911 so far. The 2002 is now only three cars short of the minimum needed to get started, and three other years are over 2/3 of the way. To help get your year included: Car reliability research Original response to BruceP: So some people are worried that I might actually earn something for the 70+ hours I spend a week? I'm providing the results for free to anyone who participates. No other car reliability survey does this. As for being transparent, I don't know how I could be more transparent. Plenty of companies hire people to post on forums as the general pubic. In contrast, I clearly identify that this is my site and my survey. The income sources, principally Adsense, are plain for anyone to see. I earn no income from selling data to OEMs, etc. As for any consensus, over 58,000 people have signed up so far, none of whom have paid me anything. Nor have I asked them to pay me anything, only to provide the data I need to provide them with information.

You're being unnecessarily defensive. First, how much you earn is not at issue. Even J. D. Power had to start somewhere. Nor do I have any problem with profit. I'm all in favour of it, actually. Nor do I have a problem with user generated commercial content. After all, that's what Rennlist is. My problem was only with the pretense that this was altruistic. You have AdSense on there, plus a banner, plus your paid tier. As for what users 'pay' you, they pay you with their data and their input time. It seems to me that the gratitude ought to go the other way, or be mutual at the very least. Respect for the user/contributor is kind of a cornerstone of web strategies like this. That's all I'm getting at. GL with the survey.

Let me know when, near the end of what has already been a long day, a group of people will be seeking to undermine what you're doing and will be claiming that you should earn nothing from it, so I can observe how I should properly respond. I don't know what you mean by my pretense that this is altruistic. I never claimed I was doing charity here, but to be honest there is a large amount of altruism involved on my part. As I said, no one here would do what I have only or even mostly for the money. No one. I have a great deal of gratitude and respect for those who have been helping with the survey. Especially if the gratitude is mutual. Those concerned I might earn a buck from it, even if this costs them nothing, and who are seeking to hurt rather than help, not so much.

Bruce - of course it is a business. So what? I participate in his surveys and get the info I want for free - just like anyone else who provides data. It strikes me as perfectly fair. I take issue with your comments about altruism. The way I see it, the ones who benefit are 996 owners and owners to be. Do you have a problem with that? Secondly and this is for you too Dell - in the past some have been quite vocal about polls on this site set up by people who had trouble with their cars. Clearly, having a bunch of unsatisfied people respond would do nothing but devalue the cars. As a statistic the results would be invalid as Dell pointed out. So, now we have a shot at finding out the truth. I doubt it is a bad as the doom-sayers believe. In fact it's possible that the 996 is a trouble free as anything else. Certainly mine was and still is in the hands of a new owner. On the other hand if people derail the attempt we will be left with speculation and nothing else. How bout we give this a chance? Regards,

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+100 on this. It has been pointed out that his effort while worthy is flawed and he refused to accept that. Just because his thread is "admin approved" does not make his efforts any more statistically valid or credible.

Thanks, Bob. I posted here in the first place because owners asked me to. I did not pay Bob or Rennlist for his approval. Believe it or not, but people sometimes do things for reasons other than money. Rennlist provided permission to post about the survey because they saw the value in what I'm doing, and Bob offered to post this thread--I did not initially request it--for the same reason. I am certainly very grateful for Bob's interest and personal involvement. To respond to something else Bob said--there is a definite tendency for problems to be much less common than forums suggest. Unlike others that conduct reliability surveys, I don't structure results in a way that makes cars seem less reliable than they actually are. I saw this survey as an antidote to the others. With this, I'd better go away until I've had a chance to get some sleep and de-stress. Too much else going on today. To paraphrase the air traffic controller from Airplane, I think I picked the wrong day to revisit this topic in the Rennlist 996 forum.

The administration didn't approve my buying the porche so scr How about a thread on stats of crashed 911's. Or a thread on guys that buy them that have never dropped an engine to work on it, changed their own oil, or thrashed a car before? Or a thread on how many guys know what aspect of downshifting gives rise to blowing gaskets or craking thinks. Then we could apply those stats to all the people taking the survey. Better have questions during the survey that point out if the participants know what they are doing. Worse yet throw all the stats out for cars that aren't original owner cars since the previous owner.....oops original owner will probably try BSing he didn't trash the car not knowing how to race a car at top rpms. Plenty of guys haven't learned from actual experience what will open the big chance of destroying their car. Might as well ask the survey takers if they have teenagers too. If so just ban them from accessing the website and throw their input away seriuosly. Best thing is the sooner we quit replying in this thread the sooner this thread goes away

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uh, nope.

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I love it!

996 owners, in spite of attempts to derail this survey, I'd like you to participate. Right now conventional wisdom is that a 996 is a ticking time bomb. I do not believe that to be the truth. If we can gather enough data we have a shot at establishing a credible data base which 996 owners can point to and take comfort in. I encourage you to ignore the doom-sayers and help prove the worth and value of the 996. Thanks,

No attempts to derail the survey have happened. Rather people have spoken their mind and you choose to promote the same anecdotal collection method that got us into this mess. Contrary to belief, most of us believe that this is a fantastic car and a very reliable one. Why in the world have I bought 4 9X6's and tracked 3 of them??? Nobody listens to the positive and rather chooses to listen to the negative. The negative comments about the 996 are miniscule compared to the positive reports we see here daily yet you (and others) think otherwise. Not only do some need a lesson in statistics but a lesson in social psychology as well. As I have said, the repository he is trying to collect is a great method to capture descriptive self-report data but NOTHING more. Not sure why you can't see that.

Will we be able to say the type of oil we use in this survey?

Bob, It seems to me that you've already made up your mind what the result should be. I'm sure that your opinion is equally valid as the data that the OP would collect because both are just that - opinion. He is collecting unstructured and statistically unsound data that is meaningless and misleading. As a moderator you are using your clout to try and sway opinion in favor of a grossly flawed survey - respectfully, that is a disservice to this membership. Dell and I are not doomsayers, we are two professionals qualified in statistical analysis that are stating that this survey is flawed. The OP is choosing to ignore our professional opinion. If we're counting the number and size of Ph.Ds, then I'd say that Dell and I add up to two to one against and I'm sure that the other Ph.Ds in the discussion are equally appalled by the methodology in play here.

I just tried to do the survey to see for myself if the questions asked were designed well enough to characterize my car. ** the engine was replaced in 2005, four years before I bought it. I don't know why the motor broke. How will this be reflected in the survey?** Anyway - the email I received said the 2002 911 is not yet included in the reliability survey. So...

Wellardmac - we have a lack of understanding here. The fact is the 996 is seen as a risky buy. The resale prices prove that. You and Dell maintain that the car is reliable. I agree with you I see this as an opportunity to collect positive opinions which might dispel the myth of 996 unreliability. In other words the same thing you and Dell have been trying to do. So why are we seemingly in opposition?

Bob, somehow I've failed to make myself understood, here. I thought I was clear that this was a slightly rankling issue about transparency. I don't appreciate having my arguments reframed for me, but such is the Internet sometimes. A subject, I should add, that I've got pretty good bona fides for commenting on. I'll pass on the survey, given the weirdness. But I do look forward to citing this episode in an upcoming speech. It's a great little story about the criticality of imputed motive in social media marketing.

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Bob, Dell and I are data driven people. It's all about the facts for us. Our opinions may be in agreement with regard to reliability. The perception of a 996 being a risky buy may be wrong and our assessment that it is wrong may both be equally incorrect. How would we know if we do not have valid data to prove that point? Only Porsche knows the correct answer. My personal experience is that the 996 is the most reliable car I've ever been exposed to, but my data might be wrong. The methodology of the OP is flawed, so that doesn't make his data/opinion any more valid. Just because something produces an answer that you might like does not make it a valid result. Data and truth matters. The point being that we might have an opinion and it is just that - everyone is entitled to an opinion - doesn't make it correct. We don't represent that opinion as fact. The OP will represent the limited data he has as being a fact and general for all 996s. That is deceptive.

I agree with bruceP and wellardmac 100%.

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By design the survey gathers information going forward, so that past experience cannot potentially bias the results. So that engine replacement won't be reportable on the main reliability survey. The analysis always looks at the past twelve months. So it won't report the lifetime repair frequency, only the frequency in the past year. There is a second form for those who want to post earlier repairs, but this only fills out the posted repair history. Repairs entered through this form are not included in the analysis. I do not ask which type of oil people use. The typical car owner probably doesn't even know. The reliability survey form used when submitting a repair is here, for those who want to see it: http://www.truedelta.com/survey.php

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"Opinions" probably isn't the best word. "Experiences" would be a better way to think of it. The survey is designed to keep opinions out of the data as much as possible. Instead, it asks factual questions, focusing on whether or not the car was repaired. Either it was, or it wasn't. While I doubt engines are failing at a high rate, it remains likely that the overall repair frequency for these cars is about average, and perhaps worse. With the Boxster, the reported repair frequencies have been very close to the average: Porsche Boxster / Cayman reliability comparisons My own opinion certainly has nothing to do with it. I periodically ask people whether or not the car required a repair, and tabulate the results. Unlike some other reliability surveys, I do not ask people if they feel the car is reliable. That would be opinion, and any opinion survey without a random sample is prone to distorted results. I have never claimed that this survey is perfect. No survey in the real world is. Luckily, flawed isn't inherently the same as useless, any more than a flawed car is useless. In this case, as in many cases, a flawed tool can be made to work quite well. In any field you'll find people who are sticklers for the rules, and who would rather have no product than an imperfect product, and others who work with what is available to get things done. I am actually something of a perfectionist myself, too much so in the view of people who know me, but stop at the point where something is still doable. I will readily claim that this survey provides valid, useful information, as attested to by the results. Look at those for the Boxster. I find them vastly preferable to no stats at all--which does seem to be the preference of some people here--and those from CR and JD Power, which are the only real alternatives at the present time. Saying that only Porsche can really know does not help anyone outside Porsche, and simply isn't true. This survey could provide very good information on the 996. The key question is whether we can get enough owners involved. The more owners get involved, the better the information will be. When I started posting here 105 911 owners had signed up. After the first thread and this one, despite the harsh criticism, we're now at 129. Still far too few, but moving in the right direction.

In the healthcare professions we're inundated with statistics on everything. I'm convinced that most of the researchers bank on us being too busy to look beyond the "conclusions" paragraph and take a critical look at the methodology. otherwise a whole host of things jump out that lead to suspect corrupt data. Voluntary surveys are perhaps the least reliable, because there is absolutely no way to filter the variables, and because they assume and rely upon the veracity of the participant, unlike a controlled study where the subjects are closely monitored. That's even before we discuss cohort size. I've seen medical studies extrapolating from double-digit patient sampling. The problem we have, and will be a problem here also, is that people tend to glance over the methodology and jump straight to the conclusions. There is nothing "wrong" with the proposed survey IF whoever reads the results will interpret them taking into account the limits of the methodology. However that doesn't happen frequently enough even with trained professionals, let alone the lay public.

Medical studies are a different case. There are far more significant variables involved (genetic background, diet, exercise, substance abuse, other drugs, etc.), the interactions among these variables are much more numerous and complex, and the subject being reported on is often inherently much more subjective--i.e. do you feel better after taking the pill? Add all of this together, and you generally need two very large random samples, with one to serve as a control group. I always strongly encourage people to look at the methodology behind any survey results, including my own. First thing to check: what questions were asked? If you don't know what was asked, then you don't know how to interpret the answer. Here's a challenge: find out what questions Consumer Reports and JD Power ask to get their stats. Both firms release very little about their methodology, and neither publicly posts its survey form. If people did look into the methodology employed by those two firms, and especially by CR, I'd have a much easier time of growing this survey. My own critique of CR's survey, which I find not only flawed but very seriously flawed: Consumer Reports survey critique They ask people to report problems they "considered serious"--opening the door wide for many respondent biases. Many people report rattles, many others only report a problem if it keeps the car from being driven. But I'm not only a critic--I'm doing my best to develop an alternative.

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I think that was meant to be a joke. Oil discussions are as hotly debated as bunk reliability surveys on this forum. Holy crap - that puts a *HUGE* onus on the owner to consistently and concientiously complete the survey. I signed up for the survey, but there's no way even I would go to the website and fill this out every time I went into my garage to work on my car. That's problem 1. Problem 2 is that I do my own maintenance which includes more maintenance and tuning than the "average" owner. This would make my car appear very unreliable since I spend dozens of hours fiddling while the opposite is actually true. I'm no statitician but I don't see this working. The system relies entirely on the discipline of the people responding to the survey, and this is inherently unreliable. The survey is structured to require high quality input but there is simply no control over the reliability of the data. Participation is voluntary and with a weak incentive. Sorry to pee in your cornflakes. I was going to stay out of this too

here is my take. I dont mind you making money. But I do mind when you try to do it passivly like you are trying to do everyone a favor. taking advantage of a situation like a guy selling caskets to a morning family and trying up up sell on the silk bedding. Thats my take on it

they are NOT ticking time bombs - they are cars that have a small set of problems that CAN be catistrophic if not fixed prior to the due date on the bomb mechanism..... you might weant to ask some of those people that do not frequent the boards, who have had thier cars explode, and who had them fixed out of thier own pocket how they feel about the ticking time bomb analogy... the motor I just helped rebuid was a TIP with ~30k, the owner had it for a month, and he stopped to get gas....after filling, turned the key and WHAM!! - $18k this thing is too much to read - so I am not going to, but for those who knoe Jake Raby, keep in mind, he is very busy fixing problems that people refuse to admit exsist and want to argue with him about the exsistance of said issues....... NO AFFILIATION

So what was wrong with making it simple? 1. Has your IMS failed and blown up your motor? Y/N 2. Has your engine been replaced? Y/N 3. Has your RMS leaded? Y/N 4. Indicate 6 speed ___ or Tip ___ 5. Indicate year ___ 6. Indicate Model ___ Thats all I really need to know.

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Maintenance and tuning do not count as repairs. A repair is when a problem is present, and then something is done to make that problem go away. An email goes out each month, so people can respond when their memory is fresh. No repair? Then only respond with an approximate odometer reading at the end of the third month. The form is short, so responding doesn't take much time. If someone doesn't respond for a little while, then resumes, we send a special email to fill the gap. Last month the overall response rate, including people who joined as much as four years ago, was 37.6%. The response rate for people who joined recently was 55.4%. These are the overall averages--for some models the response rate was much higher. Especially when you factor in that many of the provided email addresses are simply not being monitored, these are very high response rates compared to other such surveys. My cornflakes are doing just fine.

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Ed, I approved this survey because my intuition is that the alleged problems of the 996 (the M96 engines in general) are exaggerated. Trouble is, in the absence of any meaningful data, everyone assumes the worst. PAG has been no help as we all know. Jake and LN Eng. are certainly helping with cures - a good thing. In the meantime we probably all saw the thread where a guy decided not to buy a nice 996 because he was afraid of an engine failure. These fears are probably the reason why 996 resale prices are so low. Wouldn't we all like to know the real odds? I had a 2001 Boxster S. I tracked the heck out of it for 3 years and sold it to a pal who did the same for several more years. He sold it to a pal who is still driving it with no issues. Are 99 percent of the so called M96 engines like that? I'd love to know. Best,

I agree that the fear keeps people from buying the cars... my 99' has ~118k miles on the original everything and is going strong... that said it was like trying to sell a salmon after it had laid its eggs.... not much interest and thus the only way to sell would be to lower the price despite it being an excellent car - still I have heard that "maybe" around 5% of cars have had issues based on what my indy sees and what we "guess" the number of cars in our area to be is....and for me that is just a number... with out fixing the cars it could be any car and that is the scary part.... untill we start seeing cars with repaired issues going up in value or rumors of cars lasting 200k become the norm... these cars are going to suffer. knowing the data doesnt mean your car wont have it happen (IMO) fixing it before it happens "SEEMS" to be the only way to know for sure - its a good idea, but I dont see the value in the numbers if there can be no predictions made from it to prevent it from happening, thats all I am saying

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Are you a health care professional? It doesn't sound like it. The salient issue is an impossibility to verify the data. It doesn't matter if there are ten or a hundred variables, as long as one of them is that you have to take the participant's word without any verification (could be, eg., a lab test or physical examination in the case of a medical study, or shop invoice in the case of a car study). People are people whether in the context of being patients or car owners...and people are sometimes confused or mistaken, and sometimes just plain lie. That's good. One thing you might consider is requiring a faxed copy of an invoice for major repairs such as exploding engines. Another thing is can you obtain an accurate production number for a particular year. Without that there doesn't seem to be any way to accurately extrapolate percentages even if you can assure the veracity of responses.

The e-mail I got after enrolling says that the 1999 911 is not yet included in the survey... FWIW, I suspect that each owner's opinion on whether the 996 is "reliable" or not skews heavily one way or the other depending on whether they've ever had to replace the engine or not. I'll bet I've spent more on repairs to keep my Porsche on the road than I have on every other car I've ever owned combined.

Jake, the survey justs asks whether the car has needed a repair. Reliability is estimated based on the need or not for repairs. There is no opinion involved. Michael will add models as soon as he has enough data I believe. He can best answe this mind you

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It is important to keep it simple. I would not attempt to learn anything too complicated by means of these surveys. But whether or not the car was in the shop because of a problem, and whether or not the shop was able to do something to make the problem go away? People can easily handle this. Note that also, unlike many medical studies, I'm not asking people about something where they have to choose between lying and admitting that they did something they know they shouldn't have been doing. I'm not asking them how many beers they drink on the typical night, what illegal drugs they're taking, whether they've been avoiding fatty foods, or regularly flossing their teeth. Requiring a fax would probably reduce the number of responses by at least 90%--the cure would be far worse than the disease. Again, with the methods I use I don't think we're missing much. The number of repairs people forget about initially and then have to report later is surprisingly small. It is critical that the emails go out once a month. With an annual survey of the sort CR and JD Power conduct people will forget to report a fairly high percentage of repairs. I've seen a lot of evidence for this. There's no need to know the size of the population to calculate percentages.

But another issue is, a lot of his data is going to be off of the real numbers. He needs the info from the dealers. Not just our little internet community. To show you how little... Have you EVER passed a lister on the street? or even talked to one? And where do people go for info when they do have a problem???? The internet.. I am afraid to say, if all his info is just from the internet and he doesnt want to invest on hiring a company to travel the country, get mailing lists and everything else, his ratio is going to be WAY HIGH on failures. He is not going to get an accurate count... To do this he would need to invest 100's of 1000's maybe more. I am sorry to say. Its a good effort but its kinda like beating someone to death with a loaded uzi.

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Bob already responded to the "opinion" bit. The number of cars to start, and more is certainly better, is 25. The 1999, 2001, 2002, and 2003 are now all about halfway. Starting before enough cars are signed up would risk not being able to use the data people took the time to provide, so I don't do it.

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I've heard this argument countless times. It's a hypothesis that makes a lot of logical sense, but one that is overwhelmingly rejected by the actual data. Among newer cars, the average reported repair frequency is about half a repair trip per car per year, and for the best cars it's about a tenth of a repair trip per car per year. If you look at the actual results, I think you'll agree that they're far from "way high." I do think it makes a big difference that data is collected continuously going forward, and that people can't respond the instant they sign up. This survey is structured differently than other surveys for a reason.

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Thanks for the clarification, guys. I don't personally understand the uproar myself. If you're not interested, don't sign up. If you don't trust the data, why not just ignore it? I'll participate, but life's too short to worry about the reliability of a fancy car. I've almost forgotten that my 996's engine blew at 40k miles.

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No matter how little you attempt to learn, the issue still remains whether or not the data is reliable...and if it's un-verified, it's not reliable. You aren't asking them to specify their driving and maintenance habits??!! Those two are hugely important variables...and ones that people are not unlikely to lie about. You missed my point. I wasn't concerned with missing repairs, I was concerned that if someone reports his engine blew from IMS failure, that he substantiates it with a repair invoice. Otherwise what's to stop one person from using a bunch of different e-mail addresses to bump up the numbers of, just as an hypothetical example, IMS bearing failure? Of course it's possible mathematically. However it's invalid, if not downright reckless for you to extrapolate and generalize beyond your cohort. Your data is completely un-verified, and your cohort is neither random nor adjusted for variables. You don't even have positive proof your respondents even own(ed) the cars they're reporting on, let alone that what they report is factual. True you don't have the life/death liability you would if testing a drug, but the results of your survey could have a profound effect on the resale value of these autos, so I think there's a compelling ethical argument to be made against playing fast and loose with methodology.

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Actually you have confused reliability (and I have no doubt his measure is reliable) with validity. In this case, it's validity, more specifically construct validity and criterion (predictive) validty, that is of concern.

Analysis of survey data ALWAYS extrapolates from the sample to the population. It's the entire point. I'm not sure how you think the actual number of cars in the population might play into this--it's irrelevant. I run a large number of checks for errors in the data, duplicate cars, and so forth. After doing this for four years and about 40,000 reported repairs, I have yet to come across even a shred of evidence that anyone has made anything up in an attempt to influence the results. I always find a small number of duplicate entries--one to two tenths of a percent of the total--but these are generally because people don't realize that they've already enrolled their car once and then enroll it again. Under-reporting is far more of a concern than over-reporting. And it happens predominately because the average memory is poor and people "never get around to it." The challenge is to get people to respond for the cars they do have, not preventing them from responding for cars they don't have. The survey doesn't take much time, but it's not a ten-seconds-and-done-forever survey like many on the Internet. This might screen out some of the behavior you're concerned about. Lastly, I find it highly unlikely that this survey will have a significant impact on resale values in either direction. It's far from the only source of reliability information. So forgive me if I don't spend millions of dollars I don't have to fix what seems to be a purely hypothetical problem

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Wait, I thought that was the point. I thought this was a heroic effort to set the record straight about the reliability of 996s.

Uh oh! As Ricky said to Lucy......... You got some splainin' to do!

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Bruce, in fact setting the record straight is MY hope. Truedelta will simply report. For years I have watched Dell (and others) dish out pretty harsh treatment to anyone who suggests that the M96 engine is inherently flawed. I hope that with enough data we might be able to provide evidence that Dell, Wellardmac et al were right all along. My own experience with an M96 was similar to theirs - no issues at all. That's why I am puzzled by the objections to the survey. I am not qualified to debate stats with pros like Dell or Michael Karesh. On the the other hand anything reasonable which is positive will be a lot better than the conventional wisdom of the "ticking bomb" don't you think? Best,

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I do. I just think that people are worried about the potential impact of bad information, having endured all this controversy. It really takes the fun out of owning the car sometimes.

Sidebar: Bob, you know what I would really love to have? A survey like this among all Porsche owners rather than among the universe of car owners. It's only among Porsche owners that the 996 is the Rodney Dangerfield of cars, and it's only among Porsche owners that it has any kind of specific reputation at all. It would be fascinating to look at a database of maintenance and repair diaries of everybody on Rennlist, and an awesome resource. That I would sign up for.

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I never said I was trying to affect resale values, nor have I ever made any claims that my stats could affect resale values. Earlier you got your knickers in a twist because you felt I had distorted what you said. Now you're entirely putting words in my mouth. Hypocrite much?

This thread is making me ill. Why isn't there a smiley face for puking?

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Ah, the personal attack. That always works with me. Gosh, you're right. I surrender. You never had any altruistic motives at all. It's just a commercially motivated survey. Grownup much?

BruceP, Pointing out hypocrisy is hardly a personal or juvenile attack. For an example of such an attack see the earlier thread, where one of you ended up deleting such an attack. I haven't the faintest idea what works with you. Quite likely nothing. You do seem to have trouble thinking beyond a false dichotomy regarding my alleged motives. Following your logic, anyone who is paid for what they do is only in it for the money. Clearly false.

Where I come from, "hypocrite" is an insult. And you know what "works" with me? Integrity. That works. You are a commercial enterprise who is taking advantage of the hospitality of an online community to generate content for your site. The quid pro quo for this is that this same community might benefit from the resulting information. There is nothing wrong with this. It happens all the time. But if you're going to do this, in the real live grownup marketing world, you do it respectfully and honestly and with humility and gratitude. You listen. You be enthusiastic. You make people want to help you. You accept their advice, since you're also accepting their time and personal information. What you do not do is march into the community, a perfect stranger, pitch up your site as a service to mankind and then become argumentative, defensive and dismissive with people who question you. It's the equivalent of ringing a doorbell and interrupting a party to sell aluminum siding, and then yelling at people for not having the good taste to buy it. If you want to make a go of this, you need people on your side. You will absolutely fail if the character you're showing in here ends up attached to your brand. People usually pay me for that advice, but I'm giving it to you for nothing in the spirit of community. Isn't that nice?

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Forgive me for not being bilingually-fluent in statistician-speak vocabulary. I'm not a statistician for whom everything is an abstract science of figures and mathematics, I'm the guy who has to decide whether conclusions drawn from those statistics are the result of flawed methodology and hence, erroneous, so innocent people don't get sick or hurt. The proposed methodology in this case is seriously flawed, and I would not put faith in any conclusions drawn from it. If you can't tell whether data is corrupt, due diligence demands one assume it is. If the sampling was random, which this is not. You're surveying people who read internet forums. It would be like doing a study on cardiovascular health in America sampling only people interviewed eating at McDonalds... and then extrapolating your stats to the general population. You don't even make an attempt to verify that respondants own or did own a Porsche, let alone verify that they actually had the repair issues they indicate. What other errors in the data would you deem important to check for, if not those ?

To the extent hypocrite is an insult, it's one with a clear, specific basis. Unlike, to pick a random example, "moronic." The general gist of suggestions has been that the survey is fatally flawed so I should abandon it and the thousands of people who've been participating for the past four years. My apologies for not accepting this "advice" with enthusiasm, and for becoming defensive when attacked. When people do offer constructive advice, I do react as you suggest. But there has been very little such advice here. I have "yelled" at no one simply for not signing up, here or anywhere else. So this is also a blatant mischaracterization. Before I ever posted in this forum I asked for, and received, permission from the owner. This particular thread was posted by the admin at his own initiative. So I honestly do not feel like a salesman interrupting a dinner party. Throughout I have responded honestly, openly, and with an emphasis on the facts, so I see no problem with my character or integrity as represented here. True, I do not speak like a PR professional. I am not a PR professional. Oddly, when people get the PR spin, they claim to want someone who speaks honestly and plainly. But when someone speaks honestly and plainly, they ask for sugar-coated spin.

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There is not a reliability survey I'm aware of that does anything to verify that repairs were actually performed. We all assume that if someone reports a repair then the repair actually occurred, because there's really very little reason to assume otherwise and verifying every repair would be expensive. Even if cost were not a factor, and it certainly is, the negative impact of the reduced sample size would very likely outweigh the positive impact of verification. There is similarly very little reason to assume that someone is taking the time over a period of many months to report on a car that does not actually exist. It would be a fair amount of effort with no real point. One or two such responses would have no substantial impact on the results. And more than one such response would be difficult to provide without being picked up by the checks I can and do run. It's hardly the same as conducting a survey at McDonalds, as that population is engaging in a behavior with a clear connection to the dependent variable. My focus is on the overall repair frequency. The great majority of car repairs are not dependent on how the car was driven or cared for. It is not possible to maintain the electrical system, to give a key example. And, even with those repairs that could have been influenced by how the car was driven and cared for, most cars are cared for well enough that they should not have required these repairs. Major mechanical repairs before 120,000 miles are rare these days, in nearly all car models. In those cases where they are relatively common, the reason is not primary because of how the car was driven or maintained, but because of how the car was engineered.

If anything, this is entertainment. I am getting no work done and will get more popcorn. Someone pass the salt...

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Your taste in entertainment clearly differs from mine

Sorry, no, Mike. It's a pejorative, and thus a personal attack. You may observe that you think someone has presented contradictory reasoning or evidence. But once you impute motive to this, it's just an insult. I can't believe you think any of this is going to help your cause.

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Not really! I am just not sitting where your are.

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Trade seats?

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No thanks. I like my day job.

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Contradictory reasoning is one thing. Criticizing me for doing something, which I would actually argue I did not do, and then doing it yourself is pretty much a textbook case. I tried to take this as constructive feedback, and change the word in the initial post, but cannot think of a viable substitute. I can say that I was certainly not seeking to insult you, only to point out that you were doing the very thing you told me not to do. Oddly, you haven't denied the charge, but have only asserted that I should not have made it for other reasons. Help the cause? I told Bob two days ago that this thread was already doomed. But owners keep signing up, so perhaps I was wrong about that. Regardless, I didn't think Bob deserved to be taking hits for me for trying to help. At the very least we're serving to entertain chsu74.

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It can be a night job as well. I'm usually up till at least 2 AM.

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You are unbelievable. I have to say, your dialectical style doesn't do much to authenticate the integrity of your research. Apologies to the forum. I've gone about two posts too far with this man. I'll tap out now.

Are we discussing the 3.4L Engines here?

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+1. [Flamesuit on]: We should have a poll/survey on the reliability of the survey... Just adding a bit of oil on the fire. Seriously guys, cool off on the personal stuff or take your argument to the track... FM

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Only two? I'll grant that I'm lucky that the integrity of the survey relies in no way on my style of speaking.

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I'm not focusing on them. Others might be.

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But how will we verify that those responding have actually studied the methodology? What brand of oil?

Much better.

My wife might assert that your dialectical style doesn't do much to authenticate the integrity of our marriage.

Folks with technical concerns about the methodology might want to contribute their perspectives to Michael's Wikipedia entry rather than debate them further here.

I neither wrote the wikipedia entry nor do I see how it's written like an advertisement with the possible exception of the "Participation" section. I hadn't really read through it closely before now. If someone with access can delete that section, I'd have no problem with that. Note that it requests a "neutral point of view." Anyone here still have one?

Mike, it seems like one further option may be helpful in your survey to appease some 996 owners.

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...even if true, that does not validate your methodology. In general I'm inclined not to disagree with you, however in this case there are interests on both sides (remember, so far Porsche has kept their stats secret) who stand to gain or lose if a survey on the internet "proves" that the M96 is (or is not) a "ticking time bomb". Note that I'm not saying it will happen, just that it could...and therefore some specific checks should be put in place to assure that it doesn't. I can't see any way to do that other than by making people substantiate claims of IMS-related engine failure, with invoices and VIN #s. For someone who purports to be a gatherer/presenter of data, you certainly seem to have a lot of preconceptions. Not to mention, you've seen fit to lecture me on medical issues, and now you're lecturing on issues of automotive engineering. In your field it must be a great advantage to be as all-round an expert as you

I do follow up more aggressively if there's something unusual in the data, but this isn't often necessary. It might prove necessary in this case, but no way to say at this point. I certainly did not intend to "lecture" you on anything medical, and don't think I even contradicted anything you said with regard to the field of medicine. I did suggest factors that would make medical research much more complicated than my survey. Were these not true? On the factors behind car repairs, I've spent countless hours personally reviewing every repair that's submitted, over 1,000 of them a month at this point. So these aren't preconceptions. Perhaps they're postconceptions. Here's a list of the ten most recently reported repairs: 1. Coil and oxygen sensor replacement 2. Front window motors replaced - windows would not go up and stay up (anti-pinch sensors bad). 3. Replaced heated seat module on passenger side. 4. Ignition coil failed. 5. Drivers side window control stopped working. Part replaced under warrenty. 6. Check engine lite on with code - bad O2 sensor - replaced and problem gone 7. Rear bushings replaced under extended warranty 8. Replaced struts, shocks, upper bearings 9. ABS, Traction Control sensor went bad. Front hud had to be replaced. Also replace deck lid struts. All repairs covered under warranty minus $100.00 deductable. 10. Front brakes started locking up. Mechanic released them but couldn't bleed one side ended up replacing both front calipers. Recommended replacing rotors stating they had over heated and where compromised Calipers where warranty, rotors $245. This is a fairly typical set. None of these parts, with the partial exception of the brake calipers (on a 2008 minivan with 53k km), is a part subject to routine maintenance. The suspension bits could be effected by the types of roads a car is driven on, but there's no reason to suspect that the factor would be any better controlled for with a random sample of vehicles. The sensors, window motors, and modules--all very common repair items--are affected neither by how the car is maintained or how it is driven.

HINT HINT

Response to this thread has been better than I expected. Total of 144 owners now signed up, and four model years are now at least halfway to the minimum. The 2002 is closest. Not yet signed up? Details here: Car reliability research

OH FOR F_ _KS SAKE!

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HAHA WOW. sure looks like it.

http://www.youtube.com/watch?v=zDAmPIq29ro

Yeah, it feels kind of like that here. But it turns out that the people posting in this thread don't represent everyone, or even the majority. If I have to take a few hits in order to get enough people involved, I'll take them. More owners have signed up today, and the 2002 is now 2/3 of the way to the minimum.

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144 owners have signed up, and you feel you can conclude from this that the people who posted to this thread don't represent the majority. Quod erat demonstrandum. (Do you think that maybe you could continue your recruiting process without taking potshots at Rennlisters?)

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Yeah, it's funny that the community college that gave him his Ph.D (in stamp collecting) didn't teach him the meaning of "majority" and "representative sample" Main Entry: ma�jor�i�ty Pronunciation: \mə-ˈjȯr-ə-tē, -ˈj�r-\ Function: noun Inflected Form(s): plural ma�jor�i�ties Date: 1552 1 obsolete : the quality or state of being greater 2 a : the age at which full civil rights are accorded b : the status of one who has attained this age 3 a : a number or percentage equaling more than half of a total <a majority of voters> <a two-thirds majority> b : the excess of a majority over the remainder of the total : margin <won by a majority of 10 votes> c : the greater quantity or share <the majority of the time> http://en.wikipedia.org/wiki/Sampling_(statistics ) Representative sample Definition Small quantity of a targeted group such as customers, data, people, products, whose characteristics represent (as accurately as possible) the entire batch, lot, population, or universe. Yeah dude, you like totally nailed both of those! I actually kind feel sorry for you that you feel the need to take potshots at others in order to draw attention to yourself.

will the real majority please stand up?

I find it interesting that the person with the "Ph.D. in stamp collecting from a community college" is the one supposedly taking potshots. Or by "taking potshots" did you mean receiving them? I have no idea who is in the majority. Could be one way, could be the other. It doesn't really matter, since there's no need for everyone to do one thing or the other. It is clear, though, that some here would like to dictate behavior for everyone. It's not good enough that they themselves don't participate. They want no one else to participate, either.

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What's clear appears to be your habit of reading carelessly. Nobody is trying to dictate behavior to anyone. I saw the easy ride you got on the Toyota truck forum I follow, so I guess your shock at this experience is understandable. What is not is your relentless petulance. This isn't about "participating," with all the community duty that implies. It's about you availing yourself of the generosity of enthusiasts to provide content for your commercial web site. As I've said until I'm blue in the face, there's nothing unusual about that these days. But you're best to do it with a little grace and humility. The potshot I referred to was your gratuitous comment that posters to this thread didn't represent an important constituency. It was unnecessary and just got people fired up again. I do appreciate you reversing your position on "the majority", though. That, at least, is progress. Speaking for myself, if you want to continue recruiting and reporting on results, you're welcome to do it and you won't hear a word from me. But as soon as you want to start sticking your tongue out at board members, I'll probably call you on it again. Just sayin'.

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I know you find this so very hard to believe, but this is not about dictating anything. People are free to do whatever dumb thing they like, and as you're proving they frequently do. I'm fine with that. Live and let live. This is about scientifically accurate methodology. Several of us have pointed out the statistical flaws in your endeavor and you refuse to listen. You may as well pull numbers out of your butt because that's about as valuable as your "results" will be. The sad thing is that your "data" will be misinterpreted by those that don't know any better as being more meaningful than they are. You took a potshot at those of us that are trying to correct your assertions that your study has meaning. We have kept this at a professional level so far, but if you want to throw snide comments at those that are qualified to point out the flaws in your study, then you should be careful as we're also Olympic gold medal winners in snide comments and the facts are not currently on your side. You want to know why some of us are speaking out against this effort? Plain and simple, we hate to see scientifically flawed methodology represented as being meaningful and sound when it is not. As Bruce said, we had let this go and you had to go and start swiping to stir things up again - you reap what you sow.

144 owners out of 1471 views. Granted I am one of the few who have looked at this thread a few times because I am bored. Majority?

I'm the one who reads carelessly? "Important constituency" and "community duty" are your phrases, not mine. I did not say, or even intend to imply, either one. When you use words substantially different than those I actually used, and that change the meaning of what I actually said, it strongly implies that what I actually said does not support the claims you want to make.

Oh, my God, you are pathological. It's called a paraphrase. It's a legitimate device used by educated people in debate to expose inferences in rhetorical language. The words I used are not "substantially different," unless to someone for whom English is not a native language. "Important constituency" = "majority", which you later retracted anyway. "Community duty" was the inference of your verb choice, "participate", which you used rather than "help" or "contribute" in order to exploit the community's internal loyalty. It's grade school manipulation. I seriously think you should consider anger management help of some kind. In the meantime, your immature conduct has done more to discredit this ridiculous 'research' than all the statisticians in Pennsylvania could ever hope to do. J. D. Power can sleep soundly tonight.

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Sorry, but when one alternative is portrayed as "dumb" and taken by "those that don't know any better," I see that as dictating what is correct for everyone. As well as insulting tens of thousands of people.

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We judge you by your words. They speak for themselves, we really don't need to add anything else. If you don't like the label, then change the behavior. Not everyone is savvy with statistics, it's for those people that we're speaking out.

^^

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I fail to see how I've been immature. I have responded logically, rationally, and based on facts not emotions. You did not paraphrase. A paraphrase does not change the meaning of what was said. A minority can still be a very important constituency. I do not personally believe, nor did I as much as imply, that a minority should not be listened to. Saying someone might not be in the majority, which was not a good word to use regardless, is not at all the same as saying that they are not an important constituency. Going from "participate" to "community duty" is similarly quite a stretch. Using the word "participate" amounts to "grade school manipulation?" Seriously? I was never aware it was such a loaded term. In my experience it's a verb very commonly used with "survey." Search google with "participate survey" you'll find millions of cases. Are they all engaging in "grade school manipulation?"

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You clearly feel the need to add quite a bit, and not let my words speak for themselves. Why the contradiction? I wouldn't expect anyone to change their behavior in response to petty namecalling. Your posts have strayed well beyond a methodological discussion.

“Any man can make mistakes, but only an idiot persists in his error” Marcus Tullius Cicero That quote applies to both of us. You for your blind insistence on flawed methodology and me for attempting to convince you otherwise. At least I'm intelligent enough to know when I'm talking to a wall and to have good sense to walk away. 'nuff said.

If you really want to influence someone's behavior, I'd suggest not insulting them and not telling them to simply abandon whatever they're doing. My methodology isn't perfect, but it's also not fatally flawed. The advantage it has over the course you'd suggest is that it's doable.

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When you're ready, I'm going to teach you all about 'context'. It's a very important concept, ignored only by those running for office or by those arguing indefensible positions.

The way you'd like to use "context" it could twist anything into anything. This use, not my alleged disregard for it, is the sign of a weak position. You're trying to avoid admitting that you misrepresented what I wrote, because this would imply that you had to misrepresent what I wrote to make your case. I'm not even trying to engage in a debate here. I simply want to provide some reliability stats.

Mines reliable. No engine swap, 112,000+ miles. I floor it it takes off. It takes corners pretty fast too Of course I have a habit of driving it instead of other vehicles.

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This compounds your childish behavior with a straight up lie. You're trying to start a business, not "simply... provide some reliability stats." Which brings us back to our original debate, the one in which I simply suggested you be transparent and a gracious guest in the forums you raid. I cannot believe how stupid you appear to think we are.

What have I said that's childish? I have a son who is too quick to employ the word "lie." But he's nine, and I'm hoping he'll soon learn that it's not a word to be used lightly, and never without a good basis. There is no basis for it here. I'll give you some context, Bruce. This is the United States. If someone is working full time on something, and they're not living off their ancestors or past investments, they're deriving income from it. This applies to the people who operate pretty much every single site on the Internet. People are generally smart enough to know this. Especially if there are plainly visible ads on the site. It's why no one, myself included, has to go around saying, "Yes, I earn income from my site." No site owner does this, because they realize people are generally intelligent enough to know it already, not because they think anyone is stupid. Step two: So we have people generally getting paid for whatever it is they spend 40+ hours a week on. You would have us believe that all of these people do whatever they do primarily for the income they derive from it--for you it's all about the money. Sorry, but many people choose to do what they do because it's something they believe in doing or enjoy doing, with income a secondary consideration. The ideal for most people I know is to do what you like to do, and somehow get paid for doing it. This does often involve making some sacrifices, and I have certainly made quite a few. Your crass reduction of everything to money is neither valid nor the world I'd care to live in. As for "raiding" the forum, I posted here only after receiving permission from the forum owner. And this particular thread was started by the admin. But you know this already. So why the dramatic misrepresentation? I'm gracious towards the forum owner, the admin, anyone who is helping with this project, and the community here in general. I do apologize that I have trouble feeling gracious towards you in particular. Are you used to repeatedly insulting people, and having them be gracious towards you anyway?

Nice speech, but again entirely beside the point, not to mention littered with dramatic calculated fictions of what I've been saying to you. For the millionth f-ing time, I DON'T OBJECT TO YOU RUNNING A BUSINESS OR TO YOU SEEKING USER GENERATED CONTENT FOR THAT BUSINESS. I OBJECT TO YOU NOT BEING TRANSPARENT ABOUT IT AND MISREPRESENTING THE QUALITY OF THE PRODUCT . You're a very slippery fellow, Mr. Karesh. I started out this dialogue with the simple intention of giving you some feedback about how what you're doing looks. That's what marketing is all about in the modern age. From observing your wildly inconsistent and emotional reaction, I now think you're simply a fraud. See you on Twitter.

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So you've progressed from calling me a liar to calling me a fraud, again with no basis? And I'm the one supposedly engaging in dramatic fictions? I have directly responded to you point by point, the very opposite of slippery. My reactions have been neither emotional nor inconsistent. But even if they had been, I fail to see how this would be evidence of fraud. It's simply more evidence that you'll resort to baseless accusations--and fraud is a very serious accusation, people go to jail for it--in order to make your point. Though I also fail to see how this might make your point. You claim that you have an issue with my transparency. As I've said before, and consistently, I have gone well beyond typical levels of transparency. I clearly identify myself as the owner of the site. The site is clearly commercial. There's no mystery here. What I'm receiving from you is that I should explicitly state that I'm conducting this survey primarily for business reasons. But this is rarely if ever done even when it is the case. And in this case it would be a lie. Finally, how have I misrepresented the quality of my product? I have never, here or elsewhere, claimed that the results are highly precise. But the survey results do not have to be highly precise to be valid and useful. I have made two major claims consistently, from the beginning five years ago, for my survey results: 1. They are much more up-to-date than the information provided by Consumer Reports and J.D. Power. The latest results cover through the end of March 2010. CR's current results and J.D. Power's current IQS are about a year behind. 2. They provide numerical repair frequencies, not just the vague dots provided by CR and J.D. Power, for individual models. Both claims are clearly true, and are major advantages. This is the sort of reliability information I wanted. I started the survey because neither CR nor J.D. Power wanted to provide it. Sometimes if you want something done you've got to do it yourself.

Uh, this thread delivers. (But not in the good, sexy, UPS girl kind of way)

If UPS delivered like that to my house, maybe my wife would order fewer things?

If UPS delivered that way to my house I would order something every day

This thread delivers in the "is the herpes ever going to heal?" way. It healed a few weeks ago but the blister re-appeared.........

Sorry, Pete. If this thread stresses you out, consider how it makes me feel. It certainly isn't the thread I wanted, it's just the one I have to work with.

Hey Pal.......I'm not going to get sucked into this......it has gotten to the point where I do not want to log on here for fear of seeing your clueless responses. We all get it......you do not. No more posts from me on this one.

I've been a user on Mike's site with my last 4 new cars (except for the pcar) - 99 Civic Si, 05 WRX STi, 08 Infiniti G37S, and now my 04 911. If anything, I hope to gain more info about the cars I own. I am happy to participate in this symbiotic relationship. It's too bad this flame war has to go back and forth. /Rodney King Mode - can't we................

What? Pay to find something to wonder if I'm having fun in the 996? hahahaha

Good stuff Mkaresh - I don't get why people are getting their panties in a bunch over this. Though I'm not a statistician, I do realize that the survey itself is somewhat flawed in terms of methodology, and of course that's important to note, but it's still an interesting endeavor and has some value. I think this is a situation where you're just not gonna win - damned if you do, damned if you don't. Some of the more colorful posters in this thread such as Bruce and Dell - I get your point and you've said your piece, but you've repeated it and thrown in so much invective along the way that it's getting a little tiresome. No offense intended and I hope you don't take it that way - and I completely get what you're trying to say, and for the most part I agree with your general points around the fact that something like this should be approached with transparency and making clear of the methodology - I however have not gotten a sense reading through all 8 pages of this thread that Mkaresh has been trying to "pull the wool over our eyes". Is the survey flawed? Yes - but at the same time, there's a certain amount of self-selection that occurs with surveys that's unavoidable and some of the suggestions such as going door to door to shops and dealerships to make this more robust isn't realistic. Is it flawed to the point where it has absolutely no value? No - and I plan on logging my 996 as soon as I pick it up btw - I'm not some random shill, I'm very active over at bimmerforums under the same board handle. Lastly, I mean if those opposed to this endeavor just want it to die, just don't bump the thread repeating things that have beaten to death

If it gets tiresome then quit reading. And by the way, when you say "no offense" it doesn't clear you of offended. What are you Ricky Bobby? No offense here, so no worries.

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Bob, This is a noble effort, but because the survey methodology is deficient, you won't be able to prove anything, except to say that a bunch of people who felt strongly about their cars took the time to fill out a survey. For this to be valid, you'd need to sample a statistically valid cross-section of the ownership. With self-directed participation, you're not getting a representative cross-section. You're just getting a handful of people who feel strongly, making the results absolutely meaningless. Lee

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If you're going to judge me, you could at least show the courtesy of reading the entire exchange, and the one that preceded it. You might be surprised how rare it is for me to transform myself into a ***** with no provocation and for absolutely no good reason. But gosh, thanks so much for resurrecting the thread.

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wow touchy touchy - a little defensive? I did read the entire thread, and I get your point and agree with some aspects of it - I just think you guys are beating a dead horse.

Actually, the horse was not only dead but buried about eight pages deep in this site. Judging from the date stamp on your post, I'd say you were the one who dug it up for a fresh beating. Have a look, and you'll see that this was over back in May until you helpfully resurrected it. I don't know how they do things at bimmerforums, but I suspect that here, when you call anybody "tiresome", you'll probably get a little defensiveness.

I was accused of being defensive earlier, with the implication that this was somehow wrong, and wondered what might justify being defensive, since clearly none of the invective directed at me was sufficient justification. Now I know what justifies becoming defensive--being called (without singling anyone out by name) "a little tiresome." On a more serious note, in response to lml999, the people who sign up to participate in this research do not, by and large, feel strongly about it. I can understand why you'd make this assumption, but the reality does not support the assumption. Steve2112 and supark are more engaged than most participants--the average participant simply wouldn't post in this thread--yet if you read what they posted it's clear that they have no agenda, or interest in the results coming out one way or the other. They're just somewhat interested in having an additional source of reliability information and are just trying to do their part to make this information possible. I've long noticed that, for various reasons, people with strong opinions are actually less likely to sign up and participate. Part of the reason is that people with strong opinions already know what they know--they don't need further information. I feel that the reality of who participates and the usefulness of the information they provide is evident in the latest results for the Boxster. Here's what I've been reporting in Boxster forums: We have updated reliability stats for the Boxster and Cayman that include owner experiences through March 31, 2010. In terms of repair trips per 100 cars per year: 2008: 31, better than average 2006: 14, better than average, small sample size 2005: 71, about average 2003: 95, about average, small sample size 2002: 120, about average 2001: 129, about average 2000: 101, about average 1999: 129, about average Fairly consistent results from year to year, with a clear improvement from 2005 to 2006. The results for the 2000 and 2006 might be a bit lower than they should be, judging from the results for other model years. I'd like to report specifically on the IMS failure rate, but we will need more participants to do this. So far, with 180 986s participating for an average of about six months, only two IMS failures have been reported, and none since last August. The page on the site, which includes additional details: Porsche Boxster reliability comparisons

Now look what you've done, supark. The beast is risen.

Relax Bruce, like I said I agree with some aspects of what you've said - your response is out of proportion to my post. The figurative "dead horse" I was speaking to was the somewhat black and white appraisal of the survey. I agree that the survey data collection methodology is flawed, however I think it's still better than what exists to date, which I'm sure everyone would agree is a somewhat overblown and controversial mix of actual experiences and secondhand stories. I've seen similar surveys (with similar methodology) on e46 focused sites to collect data on subframe mount issues, as well as mini focused sites regarding strut tower mushrooming and they do yield some interesting results. Though not conclusive, they are useful in the very least to identify some general best practices when buying/maintaining the respective cars. That and reading through this thread, Makresh seems to be demonized as a swindler, cheat, liar, and most likely responsible for the sinking of Atlantis. Can't we all just get along?

As an 18 post veteran of Rennlist, who does not own a Porsche and was not part of the original discussion, I respectfully decline your counsel.

I don't think anyone accused me of sinking Atlantis, only of the rest of the list and, most lately, of being "the beast." Sorry you had to receive a bit of the same, supark. Some people here are interested in a reasonable discussion, but they tend not to post in this thread.

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Thanks for the warm welcome and I guess I am part of the discussion now And that's 19 posts my friend

You're welcome.

To the nay-sayers, ... I endorsed this study because in spite of the weaknesses in the stats (pointed out over and over) any half decent set of stats is better than what we have now .. i.e. the perception that the early 986 and 996 are bound to fail. Most of the reports on this site are from people who complain of engine failures - IMS, D-Chunk etc. The silent majority are not often heard from. I hoped (and am encouraged) that the majority of owners of these cars are now engaged and the statistics are getting better. Perfect? No. As Dell pointed out, only PCNA and PAG have enough data and they aren't talking. Still with enough owners reporting we can get a reasonable idea of how reliable our cars are. It beats the doom and gloom notions currently prevailing does it not? To those who vilify Michael for operating a business, I admit to being puzzled. Contribute to the data and get the results for free. Sounds like a fair deal to me. I have been participating in his surveys for years and his stats influenced my buying decisions. Regards,

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Michael, I spoken with a few Porsche techs who have yet to see IMS failures with 2006 or later 911/Cayman/Boxster (M97) engines. While this is hardly conclusive, I am curious as to whether anyone in your survey with a 2006-up 911/Cayman/Boxster has reported an IMS failure. Thanks, Joe

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No year of the 911 is in the main survey yet, though some years are getting close, so we have very little repair information for it. We don't have nearly as many 987 owners as 986 owners, but none had reported an IMS failure when I last checked a few weeks ago. I should add, for those who might be interested in helping to get the 911 into the survey, that additional details and links to the enrollment form can be found here: Car reliability research

This is really disappointing, Bob. I have repeatedly said that I don't begrudge Karesh's business model, or that it is a business, or even the concept of user generated content being used to generate traffic for advertising... and I made my initial comments from a position of having some pretty decent bona fides in this area. I made my issues clear so many times, and kept getting words put in my mouth rather than reasoned responses. Now, I get it (albeit by inference) from an Admin ?

We'll have updated stats for many years of the Boxster in about two weeks. A couple years of the 996 are now 3/4 of the way to getting started, and two more are close behind them. To help get your year started: Car reliability research

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here, now move over.

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since bob started this, where did he go, haven't seen any other admin's comment on this, whats their take, on any other thread they would have shut it down already.

I'm still here. I'll let the doctorates in statistics like Michael Karesh argue the method, I'm hoping that a reasonable cross section of data will be better than what we have now, i.e., rumor and speculation. PAG knows but they aren't saying anything, instead they redesigned the engine

If we were teenagers hacking into the car fax and compiling a database or porsche dealer repairs we'd not be acting unknowing. We'd be going to jail

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Mr. Karesh's degree is in "consumer behavior", not statistics. Out of respect to the people on this board who have bona fides in the latter discipline.

Actually my degree is in sociology, not consumer behavior, and included extensive training in survey research and statistical analysis at the National Opinion Research Center (NORC). But this isn't terribly relevant, as the analyses I'm currently performing are fairly basic and don't require the skills of a first-rate statistician. The hard part is getting enough owners involved and then managing tens of thousands of responses. Owners have been signing up, and we're close to getting started for a few model years. The 2002 is now only two cars short of the minimum. We did recently update results for the Boxster, and these provide some indication of the information I hope to provide for the 911 as well. Repair frequencies, in terms of repair trips per 100 cars per year: 2008: 36, better than average 2006: 47, better than average 2005: 49, better than average 2004: 67, about average, small sample size 2003: 94, about average, small sample size 2002: 118, about average 2001: 115, about average 2000: 92, better than average 1999: 117, about average Important note: these cars are only driven an average of 5,500 miles a year, about half as much as the average car. No adjustment has been made for this. We still need more participants to report with any precision on the IMS failure rate. So far, with 180 986s participating for an average of about six months, only four IMS failures have been reported, two of them over a year ago. To help get the 911 included: Car reliability research

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Then may I suggest you correct your Wikipedia entry. Also, your spelling.

I didn't write the wikipedia entry. My apologies for insufficiently proofreading the post and misspelling one word. Fixed, and thanks for the tip.

I take it the wounds have healed and you are back for more?

That does not prevent you from correcting it. Thus, 'wiki'. Anybody can add to or change any article. Where there are factual errors, I should think that you might feel a duty to do so.

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No more sticks and stones from me. I'm just offering Mr. Karesh some mentoring on the magic of the internets, which I really think are going to catch on.

I haven't looked into the ethics of editing a wikipedia entry about yourself. I assume at least some people would have a problem with this. With the current entry someone asked if I'd mind if they wrote one, and I said this would be fine with me. I'm fairly comfortable with the "Internets." Much less comfortable with these new app things, which I fear will replace computer-based Internet usage for many people. As for any wounds, I post about once a month either way.

Wikipedia's ethics are pretty straighforward. It's common and acceptable for people and organizations to write on their own behalf, as long as community standards are observed. If they aren't, Wikipedia and its contributors are quick to flag content that's a stub, or inaccurate, or self-promoting, as a previous version of the True Delta article was. In this particular case, it would actually be a welcome service for you to go in and correct your credentials, since they are so essential to the credibility of the article. It would actually be less 'ethical' to let inaccurate information stand.

I think you might have misread the entry. I don't see where the article says what field my Ph.D. is in. It only says "For his Masters thesis, Karesh did work with early research in consumer behavior," which is correct. Venturing off-topic, a related paper appears to have been posted online here: http://faculty.quinnipiac.edu/charm/...5%20karesh.pdf

I think neglect coupled with a high performance car is bound to be a bad combination. Maybe the expectation is that because it is expensive, it should never break. Sure, the 996 is probably significantly more complicated than it's air-cooled cousins...and more parts always introduces more chances of failures - but I have not gotten the impression thus far that it is a lemon by design. After several years of producing the 996, Porsche sure had the opportunity to tweak the design on the 997 to improve the reliability. But when I look at all the small repairs on my car so far...they were all due to neglect and or normal wear.

Dear God, is this thread still going on? Make it stop.

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Yeah, even ignoring his "statistics for toddlers" didn't make him go away. Sadly, there are some around here that fell for his sales pitch and decided to participate - more fool them.

Don't agree with Wellardmac and do what he tells you? Then you're clearly a fool, and should expect to be aggressively insulted. It takes a big ego to be so sure you're always right.

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It's not a question of disagreeing with me, or ego, it is a matter of you having clearly flawed statistical methods. We've covered this before. There's no disagreeing with fact. To disagree with clearly established fact is foolish. To persist with a flawed endeavor is called a "fool's errand" - come to your own conclusions.

Believe it or not, but I come across people who I feel are incorrect from time to time, yet I don't forcefully tell them what to do or insult them when they don't do what I tell them to. Plenty of useful information can be gathered without a large, randomly selected sample. I'm far from the only thoroughly educated person who believes this.

Okay, I'll apologize if you can convince me that you are collecting data that actually means something. You have so far failed to convince anyone here that knows anything about statistics, or experimental design that this is useful information. Simply meet the burden of validity and I'll happily endorse what you're doing, but until then you should resign yourself to the fact that those that ARE qualified to pass judgement will do so. That doesn't sound so unreasonable to me.

I understand your position and that there are others who hold it. Such discussions within my field of study go back decades, and people who adhere to one side are rarely convinced of the other. The problem isn't that you disagree with me. You're welcome to this. The problem is that you simply cannot allow for positions other than your own, and especially the way you express yourself through juvenile insults. Why isn't it sufficient to state your position? Why are the insults so clearly necessary? There are reasonable people with a knowledge of statistics who agree with what I'm doing and how I do it. And who do not agree with you. But they're not going to post here because they don't care to be insulted. Does a win really feel like a win when it's achieve through insults?

You will note that I have mocked your endeavor as foolish. I did not insult you personally - there is a difference. The fact that you take my mockery of your methods as insults is more a reflection on you than my words or intentions - you're just projecting there - your passive aggressive tone will not work on me. Those that disagree with you have not stated anything other than fact - something that you cannot refute. I state it as black and white.... because it really is black and white... there are no shades of grey here. Sorry, we're not still in school where grade inflation rules and a phone call from mommy will make Prof. Dell raise his grade. Life is harsh and judgement can be cruel when you don't have the facts on your side. I really do need to unsubscribe from this running joke.... Dell, you owe me a latte for this one.

Oh, you've stated plenty of things that aren't fact. The need for a large, randomly selected sample is not black and white for the analysis I have been performing. You refute results like those I posted earlier today--which many people have found useful--not because you can find anything clearly wrong with them, but because you reject the methods used to gather the data based on theory. You'd have us believe that no useful knowledge has ever been gained without textbook-perfect sampling methods. This is clearly false. The great majority of what you personally "know" to be true was gained through other methods. You just feel otherwise about it because it was your personal experience. You have insulted me personally more times than I care to count since I started posting here. For someone who claims to place so much value on facts, you ignore things that truly are black and white--and that remain clearly visible in this thread and the one before it--quite readily. "The facts" force you to be cruel? Sorry, but judgment is only cruel when the people who deliver it enjoy being cruel. Where the facts are truly on someone's side, and these facts are sufficient, there is no need for cruelty. The point of cruelty is to silence valid dissenting opinions. History is rife with examples.

I'm sorry that you feel that I hurt your feelings. I have mocked your methods many times, because they deserve to be mocked - you have represented them as being more meaningful than they are. I have mocked you personally only on one occasion and quickly retracted the comment because that's just not my style. I have no control over whether you take mockery of your statistically flawed methods personally.

Where did I say you'd hurt my feelings? Where have I said anything about my feelings? Another non-fact. I don't have to actually feel insulted for something you post to be an insult. "Cruel" was your own description. You realize that you are being cruel, and that I SHOULD feel insulted. The instance you deleted was only the most extreme instance, not the only instance. You deleted it only after I called you out, and for once you actually seemed to realize that you shouldn't have posted what you posted. It clearly is your style. If you're going to be the way you are, at least own up to it.

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Cruel was your word not mine. As usual you are attributing your words to others. You are not even reading posts, just making up what you would like to read and responding to posts that exist only in your head. Same MO as you tried with Macster and BruceP - we don't play games like that. I've had more productive drunken conversations with walls than I'll ever have with you. Its time for me to unsubscribe and put you on the ignore list. I'm done with you.

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My memory isn't always the best, so I performed a search to be sure. "Cruel" was first used in post #156 by you. I first used it in #157 in response to your post. Typical that you overlook even what's right here on the current page, while claiming to be stating nothing but facts. And then claim that I'm the one not reading. Can't say I'd mind if you ignore me. But I'm not going to get my hopes up. This isn't the first time you've said you were done.

This thread brings to mind a couple of internet memes: Apologies for any offense taken....

The 2002 reached the minimum and was added to the survey earlier this month. The 1999 is only four cars away from getting started, and the 2001 and 2003 are each three-quarters of the way. Those of you who have signed up to help out, thanks, I certainly appreciate it. Car reliability research

OK, this was a painful thread to work through and I have to admit that I didn't read it word for word so I may have missed something. I did end up with a (legitimate) question though, to those Rennlisters who have qualifications in the field enough to argue the methods being used in this survey- have you got a more valid non commercial survey or analysis focused on IMS failures underway somewhere?

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No. Nobody does, except perhaps Porsche. And the older these cars get and the more preventative work gets done, the less likely it is that even they have a complete picture. From a technical point of view, it is highly unlikely that even the most pessimistic IMS failure rate would fall outside the margin of error for this survey (not to mention that the methodology wouldn't capture failures in the pre-survey past). From a speculative point of view, if someone had such a failure and lost their engine over it, I'm going to guess that their first response won't be to scurry over to the computer and update their survey results. Many don't even keep the car. Sorry, but this will never be your IMS failure rate grail.

What would be the value of knowing how many IMS failures occurred in the past? What most people most want to know is how many have been failing recently. No one has to "scurry to the computer" to ensure that a failure is reported. Participants receive a regular email with a link to the survey. When they receive the email, they take a minute or two and fill out the survey. It's just not that complicated. Similarly, if the car has been sold when the ex-owner receives the email they report this and any final repairs or unrepaired problems. Because of the regular prompts provided by the emails, we get a much higher response rate than the typical survey. It's true that I cannot speak to the past failure rate. But it's now clear that, with the Boxster, the failure rate over the past year has been just a few cars per hundred. Bruce is partly right about the precision of this survey. We cannot report that the faiure rate is 5% vs 3% or 7%. But I think it's safe to say that, over the course of the past year, it's under 10%, and probably under 5%.

Personally I am not interested in how many failed this year I'm interested in how many have failed period because the failures appear to happen at a variety of ages and mileages. I have no problem with the survey your running by the way - even if some 'experts' do. As far as I'm concerned it's a bit more information and like everything else I take it with a grain of salt.

Well that's a new tactic....agree with your detractors. Taking my seat back on the couch.

awwwwww Geez!

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Different mileages, certainly, but these are all present within the past year. We would need a far larger number of reported failure to also look at the mileages at which they occurred, though. Different ages is another matter--it's no longer possible to buy a 996 that's just a few years old. I can see how it would be interesting, if not necessarily useful, to know the failure rate over time back to when the cars were new. But to do this would require doing without the methods the survey uses to prevent distorted results. As it is, I hope it is just helpful for people to know that the failure rate over the past year is fairly low, if certainly not zero. Also note that these were results for the 986, not the 996. Hoping to start having some for the 996 in February.

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I believe what most of us want to know is how likely is our car, or one we contemplate buying, to fail. Therefore the most meaningful statistics would relate the failure rate to model year, age and mileage @ failure, and driving and service/maintenance histories (avg speed/rpms, oil-change interval and oil type used, etc.). Knowing how many have been failing recently is absolutely meaningless because of all the other variables, particularly the wide range of mileages oweing to the large number of these cars that are not daily drivers. It's incomprehensible that you don't understand that. You may be a fine and knowledgeable statistician in the sense of compiling data, and if that is your only goal, fine. Most of us would like to be able to relate, interpret, and draw conclusions from such a compilation, and unfortunately your methodology (as has been pointed out a number of times by a number of people) inhibits doing so in any meaningful way.

[Image-only post; no author-written text. Original image references:] http://www.ccs.neu.edu/jpt/archive/2.6.0/images/TicTacToe2Small.jpg

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Would it be more useful to know the effects of these variables? Absolutely. But I don't see that some overall stats without these variables are "absolutely meaningless" when the overall failure rate over the past year is just a few percent. It's not conceivable that any common factor would result in a high failure rate, at least not in the near term, when the overall failure rate is so low. Also, you claim to want to know more, but posts like yours have the opposite effect.

know where lightning struck and how hot it was and wide it was and how long it was and how long it lasted and how bright it was and the temprature and relative humidity, barometric pressure, moon phase, sun spots, and what you ate for dinner 3 weeks ago and what "that guy over there" thinks about it will not give you any more ability to know when and where it will strike again just accept there is no way to know and you either dont have a failure, or you do - some cars will last 1,000,000,000 miles and some wont make it 10,000 - your choice is to live with it, prevent via some sort of replacement, cover yourself with protection, dont drive it, sell it, or lay in bed and cry... in the end you just have to pick one and do it My vote goes towards just getting a warranty and driving it till it blows the hell up - or preventing if that is not an option

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I and others can give you the explanation, but clearly we can't give you the understanding. The fact you don't (or refuse to) comprehend to such a basic and essential concept, is precisely what undermines your credibility. As it is, you are merely amassing a pile of data, with no correlational value whatsoever. Posts like mine have no effect whatsoever on you, who appears to remain blindly and stubbornly adamant to your own false notions. Thus I must agree with Ivangene that there is, to-date, no reliable means of predicting the likelihood of failure(s), nor is your data going to change that. His conclusions are the only viable ones which can currently be drawn.

If it is around 5% per annum, then half of the 01s, and 60% of the '99s would have failed. I don't think that is correct, but it's your study.

ah crap, I had no idea I was still subscribed to this. Unsubscribing so I can check out more meaningful thread like what oil to use

This datum says the failure rate may be an estimated 5-10%... among a voluntary sample... excluding those whose engines failed before signing up... taken exclusively from people who frequent internet forums... in numbers that even with a designed sample would produce a double digit margin of error. On the basis of the latter point alone, 5% in this study could therefore mean 20%. Or nearly 0%. Sorry, guys, but there is no way this study or any like it will give you a prediction for failure rate. Add to these statistical problems the fact that the failure rate over time for this engine very probably plots as a bell curve, and nobody but God in his heaven can tell you what your odds are of a future failure. You know two things: Your engine will eventually fail for one reason or another. And you will eventually do the same. So go for a drive and enjoy yourself.

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well put its about like trying to figure either of those out.... and in the end if you could figure out exactly when your expiration date was (scientificly) that doesnt mean you wont get run over by a bus and never see the science tested

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...no more ticking-time-bomb in my car - engine replaced !!!

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Was that a VT fuze (variable time) or plain jane time fuze. You know the two different types of fuzes have specific storage settings for storage. Wouldn't want you to have an unsafe condition fuze Some of us like our toys to blow up

Not sure where the 5% figure came from a few posts back. If I provided this figure at some point, I apologize. When I last looked our data suggest perhaps 2-3 percent in the past year. And many mechanical failures of this type become less likely over time. We will have some initial results for one model year around the end of the month. A couple more model years will probably follow in May. In all cases additional participants would improve the precision of the results. Car reliability research

We have an initial result for one year of the 996 based on owner experiences through December 31, 2010. With a reported repair rate of 92 repair trips per 100 cars per year, the 2002 911 is "about average," but not far from "better than average." It is important to note that these cars are driven about half as many miles per year as the typical car. The sample size is small, but the result is in line with those for the Boxster, where sample sizes are larger. Those of you who have been helping, thank you, I truly appreciate it. We'll have further updates that include at least one additional model year in May and August. With more participants, we could cover all model years and provide more precise results. For the details, and to sign up to help provide this information: Porsche 911 reliability ratings and comparisons

We have updated reliability stats for the 996 based on owner experiences through March 31, 2011. Repair frequencies, in terms of repair trips per 100 cars per year: 2002: 69, better than average, small sample size 1999: 115, about average, very small sample size It is important to note that these cars are driven about half as many miles per year as the typical car. The sample size was small, but the result is in line with those for the Boxster, where sample sizes are larger. Those of you who have been helping, thank you, I truly appreciate it. We'll have further updates in August and November. With more participants, we could cover all model years and provide more precise results. For the details, and to sign up to help provide this information: Porsche 911 reliability ratings and comparisons

I only read the first page, but " Human Nature " you gotta love it

Seems like a very useful website to me.

I try... We have updated reliability stats for the 996 based on owner experiences through September 30, 2011. Repair frequencies, in terms of repair trips per 100 cars per year: 2002: 91, better than average 1999: 92, better than average, very small sample size It is important to note that these cars are driven about half as many miles per year as the typical car. An extra note: with over 200 owners participating, not a single IMS failure has been reported for a Boxster or 911 since the beginning of 2011. The RMS and AOS are much more common problem areas. Those of you who have been helping, thank you, I truly appreciate it. We'll have further updates in February and May. With more participants, we could cover all model years and provide more precise results. For the details, and to sign up to help provide this information: Porsche 911 reliability ratings and comparisons

ok.........I'll bite.......but I was hoping you got locked in a Portapotty......

I've been contributing data on the C4S and on the Cayenne. It's very quick and easy and I enjoy seeing how our vehicles stack up to the rest of the market.

I am a new member who has been lurking. Have been considering possibly buying my first Porsche and have been looking at 996s (1999-2002 range)- glad to find this site and these posts - not sure I am going to continue my search as I can't afford a $20K engine expense on top of a car. I was hoping that the Porsches would be reliable but now I am not confident of that. Thank you all for the information you are providing here. TedFromOhio

sorry - double post.

Well Ted, you gotta do what you gotta do. Good luck with your search for a reliable 10-year old sports car. I guess a rating of "better than average" isn't good enough for you, which is fine. FWIW, my C4S is one of the most reliable cars I've ever owned.

I think Ted didn't do all his research. Sucks for Ted! I'm sure he'll go out and buy a Corvette. https://rennlist.com/forums/996-foru...e-century.html "Calculated from data collected from approximately eight million technical inspections between June 2010 and June 2011, the agency found that the Porsche 911 has been the car with the fewest reported defects of vehicles built since 2000. This is regardless of the kilometres travelled by the vehicles." From http://www.caradvice.com.au/150747/p...f-the-century/ The only other car that I've owned that is as reliable as the 911 was my Jeep (even mo' better than my old Vdub).

Don't fret, Ted. So far, your post has made the most sense than any other in this thread. I too have been and am still looking for a decent 996. This series has to be Porsches worse failure since the company began building autos. I too am amazed at all the engine failures due to a simple engine bearing flaw that a blind monkey could have designed better. Yet they still pretend there is no problem. The reason the reliability issues is so positive biased is that people hate to admit they have purchased a problem car. It just makes us look like suckers for Porsche. They can mass produce a POS 996 and call it "advanced engineering" and we fall for it. For some reason I'm still looking for a 996 but know the reality that I will be performing extensive repairs on a late model car. Sad but true, isn't it?

Oh great... here we go again.

^^if you cannot afford a $1800 IMS fix , ie LN engineering then walk away. This is a near supercar for honda money dont expect cheap to factor into it. The 997 is basically the same all the way up to 2009 so i guess by your logic they are also "POS". BTW i bought mine after lots of research, reading all the internet scares, discussing with Independant shops and will be spending $1800 to get piece of mind, no big deal. Other than that issue the car is flat out amazing and I would buy one again. I agree, here we go again......

Porsches aren't for everyone... I bought an old Alfa Romeo once... now that was a mistake!

Wow - I apologize as I certainly didn't intend to offend anyone, especially with my first post! I am probably a little paranoid but I am certainly concerned that I might not be able to enjoy a car that I might spend between $20-$30K on and everytime it made a funny noise, that might be the one time that it lunched the engine! As someone said, Porsches aren't for everyone and it is quite possible that I might not be at the income level required to enjoy such a beautiful car. Regarding the Corvette comment, I already have one - it's a 1986 convertible that I have owned for 15 years. Over the 15 years I have had to replace an altenator, some brakes, 2 batteries, and 2 sets of tires. It now has 150K miles and doesn't look like brand new, but it has been a good car - I have taken it on trips to Florida and Colorado and wouldn't hesitate to do it again. It even gets better gas mileage than any of my other vehicles. Just thought I might be interested in something new, and something that I might be able to drive for more of the year given the weather here. Again, I apologize if I offended someone or started something - not my intention. TedFromOhio

Ted, You didn't offend anyone. You're smart to do some research before you buy any car. People can be a little sensitive around here because of "forum trolls" who love to stir the pot. There are some cars out there that have had issues - no doubt about that. However, there are also many, many cars that run flawlessley for many miles. If you really want a Porsche (who wouldn't?), then keep doing your research and find a car that meets all your requirements. Good luck!

Hey Ted, some of us have had nothing but good results with the 996, I'm still very happy with my Porsche after 6 years of ownership and didn't find your post offensive. I have my original IMSB and won't worry about a replacement until I need to replace my clutch, with almost 58k miles on a MY99.

Don't sweat it Ted, the rennlist site has been taken over by folks trying to make a buck selling aftermarket monkey parts. The good news is that because of the internet stupidity you have the option of acquiring a type 996 for far less than what the cars would be selling for otherwise.

You did post, and one sows what he reaps. Or is it the other way around? Right. Not a farmer. In any case, take a look at a public "independent" database. Consumer Reports (yes it has faults) comes to mind. The 2011 "Best and Worst" issue lists reliability, as they always do. In the "Best" category are several Japanese cars, as well as the Porsche Boxster and the M3, while in the "Worst" you will find several American cars, several German cars (such as the BMW 135i ,335i, and X-series SUV). My point here is no marque is "reliable" 100% of the time, all models. Look at the data on Porsche as a brand specifically, and you will find them second from the top. That's correct, second from the top (second only to Scion). The "average predicted reliability score" as a brand is 42, where 100 is the "best score," but 52 is Scion's top score. Honda, for example, gets a 36. Of course you have to keep in mind that relatively few Porsches are sold, with respect to, for example Toyotas, so the denominator is relatively low, but if the cars imploded upon leaving the lot, you might know that. What does this mean for the 996? Nothing specifically, except based on this data set it's fair to say the marque is "reliable." Turning to the 911 specifically, you will find that their results, which I admit are odd at best, wrong at worst, give "average" reliability scores for the 2002 and "poor" for 2003, with no scores for 2001, 2003 or 2005. Ask the average 996 driver, and you'll get "great" to "piece of trash," because those with polarized experience verbalize those experiences. Although the response by KrazyK is odd, and this is the second posting today by the same poster, negatively slamming the 996 on a board of 996 owners. I avoided commenting the first time, but the second; friend, it's an odd choice. Why on earth are you "still looking" for a car you consider a "turd," and, "Porsche's worse failure?" Not that it's my business, but aren't there better ways to spend upwards of $30,000 than on a car you can't stand secondary to its presumed "lousy" reliability?

10 months in my ;02 now .. and total service cost so far was $300 - oil change, inspection and brake fluid flush ... plus I did DIY on indicator bulb holder connection ... oh and I replaced mismatched tire from PO with used P Zero for $50 from ebay, balanced front wheels ($20) and fixed wheel rash ($75) ....

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Huh? WTF, is today let's post random stuff day? I thought that's what 6speedonline was for. Now that is an intelligent statement. Our cars are severely undervalued. What other high performance sports car that originally sold for 65-85k 10 years ago be in your hands today for a fraction of the cost?

I'm not going to comment, I'm not going to comment,I'm not going to comment, I'm not going to comment,I'm not going to comment, I'm not going to comment,I'm not going to comment, I'm not going to comment,I'm not going to comment, I'm not going to comment,I'm not going to comment, I'm not going to comment

Welcome back Sneaky Pete(your avatar is great).

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Well thank you Steve.....been very busy at work as of late but have been lurking reading junk posts from outsiders. The pic is from this past year at our local track (Putnam Park). First driving with the Pilot Super Sports. What a great tire! I really like your new wheels....and envious.

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Absolutely! I bought my first one, an 04 996 C2 in 2007 with no knowledge of the IMS rage, and was willing to pay $50k+ and still think it was a good value, especially because it was a CPO car. I still have it and drive it, 70k miles on the clock, original IMS with no losing sleep or sense of urgency to replace it. The car was driven daily and year around. It is always maintained at or ahead of schedule. In October of this year I bought an 04 996 C4S with 23K miles for north of $40k with a top tier 3rd party warranty. I know that many might think I paid too much - but again I think it was a good value. I was shopping for an all wheel drive car to replace my back up ride and it was a no brainer that for a small stretch in cash I could own outright a stellar automobile. I put 4k miles on her the two months I have had her and again I couldn't be happier. This car is still as new inside and out. The problem I have now is making sure that each car is driven adequately. I am one of those guys that believes these cars need to be driven, and more than 5 miles a day. The good news is I can drive a 996 every day of the year, and I do. I am already considering how long it will take me to save enough cash to add a 3rd one, perhaps a C4S cab. That is as long as I can find another exceptional example that still has the original IMSB when I am ready.

We have updated reliability stats for the 996 based on owner experiences through December 31, 2011. Repair frequencies, in terms of repair trips per 100 cars per year: 2002: 110, about average 1999: 69, better than average, small sample size It is important to note that these cars are driven about half as many miles per year as the typical car. None of the 40 owners participating has reported an IMS failure. None of the 200+ 1999-2005 Boxster owners participating has reported an IMS failure since 2010. Those of you who have been helping, thank you, I truly appreciate it. We'll have further updates in May and August. With more participants, we could cover all model years and provide more precise results. For the details, and to sign up to help provide this information: Porsche 911 reliability ratings and comparisons

I wouldn't like the price of the 996 to rocket up in price. It will if everyone on here speaks up well about there rides. I can only speak up very well for mine so far. So I think I will keep that info to myself and not involve myself with formal recordings of the truth. God bless the scare mongers. Without them I would be still driving my 1989 Cadilac Deville lol.

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Patience grasshoppa...

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On the reliability survey note, the German survey from their towing company that operates on all the highways has the 911 and boxster in 1 and 2 place. This is based on their towing data I think. I will try to look for a link.

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This will only hold true if "hours of operation" for all vehicles on the road are the same.

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Very true. Our data suggest that Porsches, on average, get driven a little less than half as many miles per year as the average car. I think the ADAC stats are also affected by the length of the original factory warranty. If the manufacturer does the towing, then ADAC has no record of it.

It feels good to know that our cars are not unreliable overall like any other high end sports cars that are often high maintenance nightmares.

We have updated reliability stats for the 996 based on owner experiences through June 30, 2012. Repair frequencies, in terms of repair trips per 100 cars per year: 2002: 82, about average 2001: 42, better than average 1999: 33, better than average The sample size is small for the 2002, very small for the others, which could explain the variation from year to year. It is important to note that these cars are driven about half as many miles per year as the typical car. None of the 40 owners participating has reported an IMS failure. None of the 200+ 1999-2005 Boxster owners participating has reported an IMS failure since 2010. We'll have further updates in November and February. With more owners involved, we could cover all model years and provide much more precise results. For the details, and to sign up to help improve this information: Porsche 911 reliability ratings and comparisons

Great thread, one thing I would add having lived in both Europe and now the US. I not sure it would be true to say Porsches in Europe are driven much less than than the average car. They ofetn are treated as daily drivers and even only cars.

Porsche 996 worldwide production 2009-2004: 1999 911 28,040 2000 911 20,979 2001 911 27,275 2002 911 33,013 2003 911 29,547 2004 911 23,146 Total: 162,000, give or take (as cars were also produced in 1998 and 2005 for ROW) Your stated sample size: 40 That's about .025% for those of you scoring at home Michael, I enjoy your work on TTAC and think your TrueDelta model is very useful for more mainstream, large volume cars. But unless I misunderstood your sample size, just how exactly is this data valuable in any manner?

Many people have the idea that the size of the total population is relevant. It's actually not even part of the statistical calculations for determining confidence intervals, the necessary sample size, and so forth. All modern surveying is based on the fact that you don't have to survey a significant percentage of the total population to learn about this population. Surveys virtually always include a very small percentage of the total population when the population is large.

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Of course... but those types of surveys are generally conducted with some element of calculated, random selection across a given population. Self-reporting would not seem to provide the same level of validation.

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That's absolutely correct. In market research, confidence levels have much more to do with the absolute sample size than the relative sample size, and with the proportional split on a given question... but that's only true if the sample is representative, either by design or because of its sheer size. This survey is very interesting, no doubt, but it's not representative or predictive. Mr. Karesh and I have already crossed swords on this, so I'll leave it there.

Yes, we've discussed the nature of the sample into the ground. The main driver of sample size is the amount of variance. We've minimized the required sample size by initially focusing on a metric with a relatively small variance. We reduce the effect of self-selection by starting with the month people join and then continuously surveying them into the future, rather than asking about events that happened before they joined, and by maximizing the response rate. Surveys using random samples still must deal with self-selection to the extent they have a less than 100% response rate, and they almost always have a response rate far below 100%, as non-response bias becomes a factor. Ideally you'd have a random sample AND a very high response rate, but when surveying the general public this hardly ever happens. I'll grant in advance that neither of you are okay with anything other than a large random sample with a high response rate.

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Well, that would of course be nice... But an unreasonable expectation. And I can't quantify how many responses would be enough for the data to be compelling or useful, but that number is a whole lot more than 40/162,000. But since I've beaten you up a bit, let me again state that I enjoy reading your reviews and commentary on The Truth About Cars site and encourage enthusiasts to look at TrueDelta data as it relates to comparing auto purchase options and reliability.

During December I have been looking at a number of 996 cars for sale on the west coast. I have seen ads for about 25 or so. At least 20 percent have replaced engines before 65,000 miles. It seems a high number to me. How do I know the new engine with 40,000 or more miles will not have the issue. I plan to buy one with a price discount for ims replacement but sellers don't see it that way. It does give me a concern I do not have with my 964 c2 or clk55 mercedes. View of a potential buyer. My 2 cents.

Some of the replacement engines don't have a replacable IMSB.

Ivc2, I would suggest the market price of these cars is already 'discounted' for IMS issues if it wasn't for this question the cars would probably be selling for far more than they are.

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Did you note what month/year the engines were replaced? Those I know of occurred at least a couple of years ago. In earlier years the failure rate could have been about 20 percent. It is possible that those that were going to fail have mostly failed at this point, so the others could be good for the long haul. It does seem that these cars are already discounted for the IMS issue.

[Deleted because posted in wrong forum.]

We've updated our reliability stats for the 996 to include owner experiences through March 31, 2013. Repair frequencies, in terms of repair trips per 100 cars per year: 2002 911: 61, low, small sample size 2001 911: 21, low, very small sample size 1999 911: 27, low, small sample size We'll have further updates in August and in November. Given the low sample sizes, these stats are not precise. Additional participants would certainly help. Porsche 911 reliability ratings and comparisons

Same old story, more of the same drama. This pretty much sums up the reliability issues:

We've actually had hardly any IMS failures reported in the past two years, with hundreds of owners participating. I think this entry was for a repair that occurred before the member joined (but would have to check to be sure).

With the other poll showing a 9.29+% failure rate, I wouldnt be so sure of your optimism.

Michael I think you need to school KrazyK in introductory statistics and what makes a sample valid vs invalid as well as correct methodology as he is hopelessly misguided in clinging to his belief of the validity of the "poll". I know that you are actually qualified to do so... I'm not sure why KrazyK seems to believe it is valid/accurate, I do not believe for a moment that 1 of every 11 996's ever built have actually experienced IMS failure.

Walter I direct your attention back to the official 996 IMS poll which is still alive and well.

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KK - If you are talking about the poll at the top of the page then that is what I am referring to as well. What is "official" about it? How is the sample selected? How is bias controlled? Do you really believe the result is valid across the total production? 1 out of every 11 cars have experienced failure? (NOT cars that reported in the poll, but cars as in units sold by the factory, which is orders of magnitude greater than either poll respondents or Rennlist visitors.) I hope you don't believe there is anything more "official" about this poll than there would be about a poll in Crawford, Texas among registered Republicans as to who was the better of the last two presidents...

I want to chime in that my car is a DD and since bought it 3 years ago NOTHING has happened No IMS, no mechanical issues, just oil and gas. Actually, my biggest expense category has been UPGRADES

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Your so called official Poll Is from a minuscule portion of Porsche owners who are rennlisters , doesn't that tell you how off this "Poll" is ?

Wait. Aren't ALL Porsche owners Rennlisters?

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Both stats can be correct. I stated that we've had hardly any failures reported in the last two years . The failure rate you state is for the entire time the cars have been owned. My sense is that, while quite a few failed earlier, hardly any have failed recently. It's possible that those that were likely to fail have, in the great majority of cars, already failed.

Guys, this poll is worth 0.0%.

We've updated our reliability stats for the 911 to include owner experiences through June 30, 2013. (Another source is about 14 months behind.) Repair frequencies, in terms of repair trips per 100 cars per year: 2002 911: 69, low, small sample size 2001 911: 56, low, very small sample size 1999 911: 61, low, small sample size We'll have further updates in November and February. To view competitors' scores and descriptions of reported repairs, and to sign up to help: Porsche 911 reliability ratings and comparisons

We've updated our reliability stats for the 911 to include owner experiences through September 30, 2013. Repair frequencies, in terms of repair trips per 100 cars per year: 2002 911: 65, low 2001 911: 59, low, very small sample size 1999 911: 61, low, small sample size These cars tend of have low odometer readings. We'll have further updates in February and in May. The more owners participate, the more comprehensive and precise these will be. To see how competitors compare, and to sign up to help improve this information: Porsche 911 reliability ratings and comparisons

We've updated our reliability stats for the 911 to include owner experiences through December 31, 2013. Repair frequencies, in terms of repair trips per 100 cars per year: 2002 911: 66, low 2001 911: 98, moderate, very small sample size 1999 911: 54, low, very small sample size We'll have further updates in May and in August. The more owners participate, the more comprehensive and precise these will be. To see the repairs behind these stats, and to sign up to help improve this information: Porsche 911 reliability ratings and comparisons

Our reliability stats for the 911 now include owner experiences through March 31, 2014, making them nearly a year ahead of other sources. Repair frequencies, in terms of repair trips per 100 cars per year: 2002 911: 69, low 2001 911: 86, moderate, very small sample size 1999 911: 42, low, very small sample size Thank you, once again, everyone who has been helping. Next update in August. For a deeper dive, including the stats for other cars and repair descriptions, and to sign up to help improve this information: Porsche 911 reliability ratings and comparisons

We've updated our reliability stats for the 911 to include owner experiences through June 30, 2014 (making them about 14 months ahead of some others). Repair frequencies, in terms of repair trips per 100 cars per year: 2003 911: 90, moderate, very small sample size 2002 911: 51, low 2001 911: 75, low, very small sample size 1999 911: 12, low, very small sample size Like most sports cars, these average about half as many miles as the typical car per year. Next updates in November and in February. The more owners participate, the more comprehensive and precise these will be. For repair descriptions, the stats of other cars, and to sign up to help improve this information: Porsche 911 reliability ratings and comparisons

We've updated our reliability stats for the 911 to include owner experiences through September 30, 2014. Repair frequencies, in terms of repair trips per 100 cars per year: 2003 911: 84, moderate, very small sample size 2002 911: 72, low 2001 911: 79, low, very small sample size Additional participants always helpful (I'd love to be able to drop the disclaimers and cover more model years). To view the repairs behind these numbers, check the stats for other cars, and sign up to help improve this information (next update in February): Porsche 911 reliability ratings and comparisons

I want to participate but the survey form but it is very convoluted and opaque. Can't you just have a blank page and each owner puts down their service history?

Sorry for the trouble. Are you referring to the form for the reliability survey, or the one for repair histories (for reporting repairs before you joined)? The trouble with a blank form for the main survey would be: 1. Even if people entered sufficiently complete information, I'd never have the time to convert about 2,500 such responses each month to data that could be analyzed. 2. Even with the current form for the reliability survey, many people provide incorrect information. I use the redundancies built into the form to correct most problems without having to recontact the member. Many of the questions help determine whether or not the reported problem should count for the purpose of these stats (exclude problems caused by previous work on the car, etc.). People often won't remember to mention things like this--or even whether a repair was attempted, or successful--with a single open-ended question. If you're referring to the repair history form, it does need to be revised, and we're currently working on a solution that will integrate it into the main survey. Just having two forms can be very confusing.

We've updated our reliability stats for the 911 to include owner experiences through the end of 2014. Repair frequencies, in terms of repair trips per 100 cars per year: 2004 911: 40, low, very small sample size 2003 911: 67, low, very small sample size 2002 911: 66, low 2001 911: 61, low, very small sample size We'll have further updates in May and in August. The more owners participate, the more comprehensive and precise these will be. For the details, and to sign up to help improve this information: Porsche 911 reliability ratings and comparisons

So, how have these cars been doing lately? Our reliability stats for the 911 now include owner experiences through March 31, 2015. (Others are nearly a year behind.) In terms of repair trips per 100 cars per year ("low" is best): 2004 911: 40, low, small sample size 2003 911: 33, low, very small sample size 2002 911: 77, low 2001 911: 45, low, very small sample size 2000 911: 95, moderate, very small sample size Next updates in August and November. Additional participants very much needed to provide precise stats for all but the 2002. (Which would also benefit from additional participants.) For repair descriptions, the stats for other cars, and to sign up to help improve this information: Porsche 911 reliability

Our reliability stats for the 911 now cover the year ending June 30, 2015. (Others are over a year behind, and so report how these cars were doing when a year younger.) Repair trips per 100 cars: 2004 911: 52, low, small sample size 2003 911: 10, low, very small sample size--stat too low to be accurate 2002 911: 81, low 2001 911: 45, low, very small sample size 2000 911: 109, moderate, very small sample size As always, additional participants would be very helpful. With larger sample sizes there would likely be smaller differences from model year to model year, but the 2001 through 2004 would likely still be better than the average car of this age. For the descriptions of all reported repairs, results for other models, and to sign up to help improve this information: Porsche 911 reliability ratings and comparisons

Ok, I admit, I haven't read the entire 17 pages How is 81 repair trips per 100 cars low or even 52 trips per 100?

It's low compared to other cars of the same age. These are now fairly old cars, and they tend to be driven less and maintained more thoroughly than the average 12-16 year-old car. A large percentage are not daily drivers. In the past I've noted this, and should have this time. The relative comparison isn't entirely a fair one.

We've updated our reliability stats for the 911 to include owner experiences through September 30, 2015. In terms of repair trips per 100 cars per year: 2004 911: 47, low, small sample size 2003 911: 12, low, very small sample size 2002 911: 104, moderate 2001 911: 62, low, very small sample size For the details, including repair descriptions, and to sign up to help improve the precision of this information (additional participants would be very helpful): Porsche 911 reliability ratings and comparisons

We've updated our reliability stats for the 911 to include owner experiences through the end of 2015, about eight months ahead of other sources. In terms of repair trips per 100 cars per year--lower is better: 2004 911: 32, low, very small sample size 2003 911: 67, low, very small sample size 2002 911: 105, moderate 2001 911: 67, low, small sample size No stat, or a small sample size? Then we especially need more owners involved for that model year. For the repairs behind these stats, reliability information on other models, and to sign up to help improve this information: Porsche 911 reliability ratings and comparisons

We've updated our reliability stats for the 911 to include owner experiences through June 30, 2016. Reliability information elsewhere is based on a survey conducted in April 2015--well over a year ago. Repair frequencies, in terms of repair trips per 100 cars per year (lower is better): 2004 911: 54, low, very small sample size 2003 911: 47, low, very small sample size 2002 911: 117, moderate 2001 911: 89, moderate, very small sample size I'd very much like to get rid of the sample size notes and provide highly precise stats--merely need more owners involved. For the repairs behind these stats, reliability information on other models, and to sign up to help improve this information: Porsche 911 reliability ratings and comparisons

We've updated our reliability stats for the 911 to include owner experiences through September 30, 2016. In terms of repair trips per 100 cars per year (lower is better): 2004 911: 58, low, very small sample size 2003 911: 51, low, very small sample size 2002 911: 84, moderate Additional participants always helpful, especially for years without stats or with small sample sizes. For the repairs behind these stats, reliability information on other models, and to sign up to help improve this information: Porsche 911 reliability ratings and comparisons