Oil change input needed

Hope I’m not beating a dead horse here, as this is a frequently discussed topic here. But after reading numerous posts and researching the various manufacturers websites, I still have questions, hopefully someone can weigh in on their experiences. ‘08 Boxster base , 50k miles, ready to perform an oil change. Had decided to go with Liqui-Moly and visited their website. There are apparently three versions recommended for my vehicle, using 5W-40. I was almost ready to choose the Liqui-Moly Top-Tec 4100 when I came across two of their versions I hadn’t heard of before. There is also a Liqui-Moly Leichtlauf High Tech, and a new one called Liqui-Moly Molygen New Generation, with molecular friction control(?). They all meet the Porsche A40 standard, but I’m growing ever more confused. Anyone with knowledge or experience with these variants? Welcoming all input from our informed community.

I've used Liqui Moly on and off for about 5 yrs. I'm unfamiliar with the TOP TEC 4100, but the description "Suitable for alternative fueled CNG and LPG vehicles. Use with extended oil change intervals as per manufacturer." seems to say it was designed for a different use case that I expect we're shooting for. I've used the New Generation more frequently (when does it stop being new ?). It has a fluorescent property to make tracing oil leaks easier, but I don't have any leaks. So other than the Molecular Friction Control marketing hype, I don't know if there's any benefit over the well regarded Leichtlauf High Tech. Honestly I don't think any of those 3 would be a bad choice. BTW, just to try something different, I went with Motul 8100 X-Cess Gen2 5W-40 for my recent oil change. Probably will stick with it. Seems to slightly diminish some of the mechanical engine noise.

Motul 8100 X-Cess is an excellent choice. The only reason I don’t run that is because I don’t put enough miles on year-over-year. I change the oil so frequently that Mobil 1 euro is more than adequate. I don’t go anywhere near the Porsche recommended interval.

Thanks, RSchwerer, Boristhespyder for your responses and input. I also noticed the ‘suitable for CNG and LPG vehicles’ and took that to mean it will ‘work’ in those vehicles although it doesn’t appear to be specifically designed for that use. When going to the Liqui-Moly website, it allows you to choose your vehicle make, model, and year and all of those I included have a “Fits your application” result, as does FCP Euro on their website, so I’m assuming it would be correct if I selected any of those choices. And the ‘New Generation’ with molecular friction control sounds great on paper, although marketing these days can be so misleading. I will look into the Motul 8100 X-Cess further, Boristhespyder, as they are also top rated. I typically do all my own maintenance but at my last necessary visit to my Indie, he replaced my rear main seal and thus had to change the oil and he uses Mobil 1 exclusively, and has been a Master Porsche tech for 40+ years so I guess he knows a thing or two also. Maybe I’m just clutching at straws, as I’m sure all of these oils are more than satisfactory, as my Boxster is used less than 2k miles a year, never tracked, and only driven spiritedly. Enough to make your head spin. But I do appreciate the feedback. That’s why this forum is the best. The collective years and experience that everyone shares here is priceless.

If you put on two grand a year, and you change it every fall to prevent moisture from sitting over the winter in the crank case, then Mobil one euro is all you need. It is a Porsche approved oil as well. Frequency of oil change and quality of oil have an intersection at the low mileage point. IMO it would be a waste of my money unless I was going to drain it and put it in my truck! 😂 as it is, I am throwing away perfectly good filters, but I call that cheap insurance, and since I have the spin on adapter, they are way cheaper than the Porsche cartridges.

Right on about the intersection of miles vs time. I‘ll never reach the mileage interval needed so I do it yearly. Luckily, living in Southern Florida I don’t have to worry about the winter layover, and I’m fortunate enough to keep my Boxster in my garage 24/7, unless I’m out for a spin. Side bonus is that it is protected from the harsh Florida sun, being in the garage, so my dash, interior, and rag top are crack-free and not faded. My next decision, after narrowing down the finalist in my oil quandary, is to choose to go the spin-on filter adapter route or stick with the original setup.

I was fine with the OEM setup until replacing the entire assembly, it became problematic somehow to tighten perfectly. So now the car has one aftermarket part! I was surprised how heavy that spinner adapter is, I would’ve been happier if it was lighter. But it makes it quite a bit easier and I can toggle between Napa Gold filters and Mahle filters both of which are good quality. It’s getting new filters at about 2000 miles itself, it’s overkill to the max but it’s how I roll. Since 2,500 miles, my car has never had an oil change that I didn’t do, that’s thousands of dollars of savings so I feel it all equals out in the wash. PS my car has never lived outside, except for when it was sitting on the dealer lot. Same with my DD. The difference of this practice over time is quite easy to see.

All the oils mentioned should be fine in this application. You aren’t stressing the car much. The two keys are the annual change even though mileage is not high AND making sure to get the car up to temp when driving it. Many low mileage cars are driven over and over again on only short trips. They don’t get fully warmed up, and all the wonderful benefits of a fully warmed up car are never realized. Most of these benefits are oil related. Both the oil in the crankcase as well as the AOS related oil/vapors.

You are so right about that. I’m a stickler when it comes to the engine temp. Even if I pull it out of the garage for a wash, I always run it for 15-20 minutes before shutting it down. It was once explained to me to picture the oil like molasses. At room temp, molasses is as thick as tar. Start the car, the oil begins to circulate over all the internals. Shut it down cold and all that ‘tar’ just clings and sticks and coats, clogging up all the passageways of lubrication. Once up to temp, and properly thinned it will drain nicely back into the sump and oil pan.

I've said it before, tested it myself, and now Blackstone has a podcast about it: Oil does not "age out" within reasonable time-ranges. Even sitting in a car, the moisture theory doesn't hold water (pun intended). I tested this with my own vehicles and my friend's 70s era GM (back when engines had breathers and more air in them versus current vehicles which are tighter) which was buried in the snow outside all winter (northeast MA). Never have I seen extra moisture in UOAs or any extra wear either. As far as I have seen, no one has shown any data proving this theory, but I encourage anyone to share if they have it.

Which watch is more accurate than the other? Is a Rolex more accurate than a Seiko just because it is more expensive? In the old days, I searched / researched (especially on BITOG), tried different oils, etc. but a long story short and based on my friend's input (who is a transmission fluid R&D guy for Infineum), I landed on the following: 1. as long as you are not racing your car (and we typically drive about 5000 miles a year) 2. just get the one that meets the spec (i.e., A40 in our case, although DT40 is not simply because Driven doesn't want to pay / participate in the program) 3. We typically use M1 or Castrol (or whatever is on sale) 4. and change once a year, we are good (and he thinks this is over-doing it since our manual says 2 yr / 20K; while we both feel bad for the environment but do it anyways because of IMS / bore scoring) 5. Yes, PAO / Group IV is more expensive but PAO is mostly used to extend OCI (less ash) and draining old oil is better than extending with PAO 6. I think more expensive, boutique ones have more PAO or PAO-based, hence the price 7. FYI (my posting earlier this year), with my UOA - https://www.planet-9.com/threads/us...lysis-987-1-2-7-m1-0w-40-5000-mi-11-months.255849/?post_id=2229710#post-2229710 Since oil is rather a personal choice (just like a watch), I would just go with whatever you want to try

Quotes source post: 2229710

Thanks for your take on the oil quandary, and including the link to your Blackstone report. Many posters here seem to agree on the importance of an oil analysis from time to time, and yours is the first I’ve had the chance to study.

2008 987 Cayman S here with 145k miles, garage kept in Texas. I use DT40 changing every 4-5 months myself and call it a day. I used to use M1 and nothing wrong with that but due to my paranoia about bore scoring I switched to DT40 for added peace of mind. I used to use Liquimoly in my beemer before the Cayman , it’s a good choice too but frequent changes is probably more important than the slight differences of these all quality oils. Reading about DT40 it just seemed more scientifically engineered for Porsche application. Also, top tier fuel is equally important to me as frequent oil changes.

Agreed. I never idle to warm up. Start and immediately drive keeping the rpm’s between 2 and 3k until the the engine reaches straight up operating temp before giving it the pedal.

By the way, how long does the oil take to reach the operating temperature. We have a coolant gauge but I know oil takes longer. Not an apples-to-apples comparison but our Boxer engine Subaru takes at least 10-15 mins for the oil to reach the operating temp (of 200+) even if the coolant is "in the middle." Tried to access OBD II but my Torque Pro (via Bluetooth) DOES NOT shows the engine oil temp.

That’s a good question, I never worry about it and just go by the gauge. I’m not racing anyone and in my case, it takes at least ten minutes to even get out if the neighborhood anyway so I’m not getting on it hard yet.

Appreciate and understand the viewpoints, but which is worse in the long run? Sometimes I need to pull one car out of the driveway to clear the path for one to leave the garage, there are four in my stable, and don’t really have time to drive around the neighborhood, maintaining the 2-3k rpm range, when I need to depart. Let it run for the short time it takes to juggle vehicles, or start it, move it, then shut it right down again? Certainly don’t want to invite bore scoring or engine damage of another variety, but not sure which is worse in the long run.

My feeling is that it is fine to have a few short "trips" such as just moving/rearranging cars in your driveway, as long as you occasionally take them (all of them, not just your 987) for nice long drives to reach normal operating temp long enough to burn off any accumulation of fuel/water in the oil and get all the moving parts lubricated. I don't treat my Cayman different than any of my 4 vehicle fleet in this regard, but since it is now mostly a garage queen, I am more conscious about the need to give it a good workout occasionally.

I have the same model (and the same bore score "worry"), and have been thinkng about switching from the LM HIgh Tech to the DT40. How have you found the DT40 in your Cayman ? Mine is currently at 94,000km (55,000mi).

I’m straddling that same fence. Currently using Liqui-Moly but this thread has a lot of DT40 fans so sifting through the many sources and comments to reach a conclusion. This oil change will also include gearbox oil change while it’s off the ground and a purchase of a Foxwell scanner to reset the Service Reminder when done. A response from Foxwell Diagnostics indicates that the NT530 Plus can receive updates over Wi-fi, eliminating the need for a PC. Should be a nice project while the weather isn’t too hot here.

Hey Don, I change oil every 3 months. I realize that is probably excessive but mine is a DD with 150k on the dial so why not. M1 is fairly cheap. I have used DT40 but it’s pretty pricey for frequent changes and I’m not sure how much difference it makes on my old rattler that is probably headed for a rebuild sometime anyway. It does seem to purr with clean oil so that’s the route I’m going. I have let it go longer and sent samples into SPEEDiagnostix with a clean report, so…

For the record, changing oil too often leads to increased wear on the engine: SAE International | Advancing mobility knowledge and solutions You can do what you want, but the data shows it's not helpful... and it's also wasteful.

+1.....I heard you need sufficient operating time to build up the tribofilm. Have a friend who is a transmission fluid r&d guy and he think even 5k /1 yr (vs the manual s 20k / 2yr) is over doing it.

HAHAHA, I never heard too “clean” of oil would be harmful to an engine. Mine is always “carbon-ated” when I drain it. Oh well damned if we do, damned if we don’t. Drive it like you stole it and don’t worry about it.

Wow...you just can't win. Change oil too frequently, bad. Change oil too infrequently, bad. Must be a happy medium between 5,000mi and 20,000mi...12,000mi?

The only REAL reason to change oil is because there are too many particulates, the oil has changed viscosity, or the additive package has depleted. That's why UOAs (used oil analysis) are so helpful, because you can see whether a change is really needed. Changing early is simply not beneficial for many reasons (wear, waste, etc). HOWEVER, the reality here is that the wear levels we see with oil analysis are (relatively) small, so it's not like you're going to immediately-destroy a motor by doing changes too often... but my point is to show that it's not helpful (and actually worse) and it's wasteful in various ways. People think "more is better" but, In my experience, rarely is that true... "more is better" is a habit that people (not targeting anyone specifically! Just speaking "in general") really need to get out of...

Well said. Thanks Schwinn

I think it goes a bit beyond even "more is better" - early oil changes make the changer feel good about doing something for their car. They get gratification and pleasure doing it. It's pleasurable and the pleasure is fun to repeat. As with most pleasurable things, it can become addictive. Is it useful? Unless the engine is actually seeing severe use, no - not useful - but pleasure has its own value. If the change is combined with an oil-analysis each time it's done, it could be useful in alerting the owner to any changes in wear patterns. On the pre-.2 engine this has a use.

Agreed, there is a "pleasure" aspect, I suppose... but it's still wasteful and (technically) more damaging. My take is, if you want the pleasure... drive it! Again, people can certainly do whatever they want, and I'm just expressing my opinion, of course (being the engineer that I am!)... and the extra damage is likely not a huge deal... but it's not "better", that's all I'm saying.

That’s very interesting. I’ve certainly heard people, including experts, say that oil can go longer than many people thing. For example, I’ve seen Blackstone reports say a few thousand more miles can be added to the oil change interval. But this is the first time I’ve seen something saying that used oil is an improvement over fresh oil.

That definitely was an interesting study on the protection levels of what we would typically call ‘old, used, past its useful life’ oil. But according to the write up, once looking at the molecular level and chemistry going on, it seems that it’s not so much that ’old’ oil is better than ‘new’ oil, but that past a certain point the oil with some mileage on it creates better anti-friction properties than freshly changed oil inherently has. So, using quality oil with right additives and protective agents probably can go a bit longer than we used to believe, mileage-wise.

Yeah, that's the weird thing... that old oil creates a different film than new oil does. And this old-oil-film is more protective than new oil is. Maybe this will lead oil companies to identify what, exactly, is with the old oil that is beneficial, and how to include that in new oil. It should also be noted that this is a second study on the matter. They talk about an earlier one that found similar results as well... this one simply took it further with real world data on real cars, I think (I haven't read the old one). I generally run my oil as long as I can, based on UOA data. Blackstone has always told me that my results have been good on this car (and my others). Even my over-boosted Subaru was able to get to about 10k OCI (oil change intervals). I will note, on that car, M1 was NOT ideal for this, and I was actually using Shell Rotella T6 , because the turbo there is known to be much harder on oil (and M1 is well known to shear-down in those motors, and in general - I see it coming down on my Porsche as well). I forget what my last OCI was on the Porsche , but it was close to 10k and still looked great. Again, we can all dive into the nitty gritty, and maybe this discussion needs to move to another thread - I'm happy to share more info that I've learned and collected. But, the point of all this for me is to show that over-changing oil is harmful to engine wear, contrary to what people feel. Also, unrelated to this study, oil doesn't "age" in an engine or even on the shelf... time based changes are not necessary (within reason, of course). If people want to change more often, or because it feels better, then so be it... but know that it's not "harmless" nor "better" for longevity or the engine.

Interesting thread. I’ll admit that I have not read the paper, but wonder if it can somehow be related to the assertion that filters have a sweet spot of filtering. Before they are too loaded up, they supposedly improve their filtration efficiency. This assertion is coming from an interview I watched with Lake Speed “The motor oil geek” who interviewed a filter manufacturer. I believe they were primarily talking about air filters, but think they generalized that to all filters. By dubious logical extension, I wonder if the extended OCI kept a similarly performing oil with an improving performing filter to give the net improved results. Very speculative musings above…