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YOUR RESEARCHEngine Oil viscosity rating
Leading reported evidence
Replace oil and the filter was
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I just changed the oil and the filter was clean, except for some small plastic bits that are probably from the chain guides.
Leading evidence: 'Replace oil and the filter was' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, the most frequently mentioned possible cause is 'tag' (1 discussions; 0 report identifying it and 1 suggest it). The most frequently discussed action is 'Clean except' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
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Performed · outcome unconfirmed · Original poster
The only reason I ask is I'm running 10W40 castrol syntec right now, when my car is hot due to sitting in traffic the oil pressure gets down to 1bar.
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I used Mobil 1 0W40 for a while and switched to DT40 which is 5W40 very happy with that.
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Suspected cause
It approves a number of oils and the oil manufacturer then adds the Porsche "A40" tag to the oil label along with probably the tag from VW, Mercedes-Benz, BMW, etc.
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Suggestion
I will be switching to DT40 (already on order from Amazon) on my next oil change due to the development and recommendations of Jake Raby, Flat 6 Innovations.
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Might mention though I ran 0w-40 for years in both my Turbo and in my Boxster and both were driven in very high ambient temperatures and never suffered any oil (or other) issues from the heat.
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tag
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Suspected cause
It approves a number of oils and the oil manufacturer then adds the Porsche "A40" tag to the oil label along with probably the tag from VW, Mercedes-Benz, BMW, etc.
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Hi folks, my car is missing the user manual so I searched online and it seems at ambient temps above 50F (I live in norcal so it doesn't get cold here and I might not drive it much in winter) I can use 15W50.
I have a 2000 996.1
The only reason I ask is I'm running 10W40 castrol syntec right now, when my car is hot due to sitting in traffic the oil pressure gets down to 1bar. I have the LN engineering low temp thermostat in the car and also a new water pump.
At normal temps it idles at 1.5bar
I'd feel a little more comfortable if the oil pressure was higher running the 15W50 oil.
Thoughts??
0W40 or 5W40. I don't think 15W50 nor 10W40 is recommended, but there are much more knowledgable people here! Brand creates disagreements. I used Mobil 1 0W40 for a while and switched to DT40 which is 5W40 very happy with that. So pick which one you are comfortable with. There is an oil pressure fix that may help, involves changing a pin and spring from the bottom of car. No disassembly required. I think it is part of oil pump relief system. Search the forum.
I too live in Nor Cal and have been using Mobil 1 0-40 and when sitting in traffic in the bay area in 90 deg+ temp the oil pressure never goes below just under 2 bars. I will be switching to DT40 (already on order from Amazon) on my next oil change due to the development and recommendations of Jake Raby, Flat 6 Innovations.
Motul 8100 Excess (5w40), Mobil 1 5w50, and if adventurous, perhaps Liqui Moly 10w60 or Castrol 10w60 should things get (and stay) really hot. Others can comment on the DT40 by way of hot temperature viscosity dynamics, but it certainly has its adherents.
My car has spent its entire life in upstate SC. It can get cold in the winter, but not that many days below freezing. My 1999 C2 just rolled over 90k miles and it has ALWAYS run 15W50. Michelin Research and Development, who owned the car for the first 14 years of its life, even wrote "use Mobile 1 15W50" on the intake plastic where it is very visible when you open the engine hatch. I just changed the oil and the filter was clean, except for some small plastic bits that are probably from the chain guides. I will continue using 15W50.
Apart from it not getting that cold here (I may not even drive in the 911 when its that cold anyway, its a second car) Mob1 15W50 is what my BMW bike runs too and is available at walmart so its convenient.
I did some online reading and 1 bar idle pressure doesn't seem bad, but I think I'll be switching to the 15W50 if its porsche approved considering where I live.
I'm not an oil expert but use 0W full synthetic because it is my understanding that the first number (0W) is the cold start viscosity and second number is the at temp viscosity.
Cold starting an engine is where the most damage and wear occurs in an engine and my thinking is that I want the best protection at start up and using a 0 weight oil is the thinnest at cold start and lunricates and moves to where it needs to fastest and the best at cold start. Once up to temp the oil become a 40.
Thats my understanding. I could be totally wrong. I think using a cold start weight that is too heavy will speed up the wear on the engine because the cold start lube isn't as quick. Also cold start can be in 100 degree weather. It just means starting the engine after it's been sitting for a while, even in 100 degree day.
I'm no oil expert either but the above makes since to me. I was about to write something similar. I know there are many other threads on oil to read and now is a good time to become educated (or more confused).
You're right, the first number means a 0W oil will flow the fastest when cold. Ideally the largest range in theory would be best so 0W60 for example, so thin when cold but holds viscosity when hot.
However to get the increase in range they have to add other components in the oil which make it less optimal in other areas. Its all a trade off.
So, did what we all should do and did a search on Oil Viscosity and instantly found the following link. Not sure if the author is an oil expert but he sure put things in perspective.
https://redirect.viglink.com/?format...he%20author%3A
I am running 15-50 for the summer. Cold start at 32F ambient is different than cold start at 70F ambient. The higher the temp, the faster the oil will flow. There's probably very little difference between 5-50 and 15-50 at 70F. There is a difference at 32F, and at 0F, even more so.
1 bar at idle is still fine, but you might only gain 0.25-0.5 bar switching to x-50, but go ahead if you want. Just change it back if cold temps drop significantly. I will run 0-40 when temps start to drop into the 40s or 30s.
No it would NOT be. You want the tightest range that meets the specific requirements and specifications set by the automobile manufacturer, for the specific environment of operation.
To get an oil, for example, with a range like you mentioned, 0W60, you have to have a LOT of additives and friction modifiers. Those are the things that break down first, and cause the oil to shift out of spec.
To exaggerate this point, look at our manual transmission gear oil spec. It's 75W90. A very tight range, only a spread of 15 points. Why not "invent" a gear oil of 0W90? For the same reasons to have good cold flow? Well, probably with all of the required friction modifiers to make a 0W90 oil, it would never hold up for 100,000 miles.
Lots of guys commenting on the DT40. Just remember, when moving over to this oil, that you should really do a 200-400 mile engine flush, first, with BR30, to get the full and fastest, benefit of the DT40. Especially when moving over from the Mobil product line due to the additive packages fighting each other from the cross pollination.
I don't think the 75-90w comparison can work. I think that rating is an entirely different class rating. I read that the viscosity is actually closer to regular motor oil in the 40-50w range. And also, I don't think viscosity in linear with respect to temperature, so 15 points up high is not the same as 15 points down low.
No oil expert nor engine design guy here, but I thought the car manufacturers specified a certain weight oil to meet the internal design of the engine first which includes variations for temperature extremes. I.E.: To properly protect based on internal clearances and functionality for items such as bearings, rings, valve trains, other moving parts, etc...Have I been mislead all these years?
Like I said, it was to exaggerate a point. Regardless, you want the ranges to be as tight as possible (to meet the car's spec and enviro) for the reasons stated regarding the additive package and friction modifiers.
Unfortunately the owners manual regarding oil is out of date.
Porsche does not approve of any 10w-XX, 15w-XX or 20w-XX oils.
There are a number of 0w-40, 5w-40, and even one 5w-50 oil approved for use in these engines.
My local dealer service department supplies me with the latest approved oil chart/list when asked. I picked up one a few weeks ago.
I can tell you based on my experience with my 996 Turbo I do not think you will improve your engine's hot idle oil pressure by switching to a xw-50 oil.
When I switched both of my engines from 0w-40 to 5w-50 oil (because while it doesn't get very cold where I live/drive it gets pretty darned hot) the Turbo's hot idle oil pressure didn't change.
Might mention though I ran 0w-40 for years in both my Turbo and in my Boxster and both were driven in very high ambient temperatures and never suffered any oil (or other) issues from the heat.
Also have to point out that the "1 bar" reading from the gage might not be accurate. Assuming it is 1 bar is a bit over 14psi and that's plenty of hot idle oil pressure. Remember too that the oil pressure sensor is in a camshaft cover and this is about as far away from the oil pump as it can be so that "1 bar" is way up "top".
IOWs, the engine's fine. My recommendation would be to switch to an approved 5w-40 oil or even back to 0w-40 oil (especially if you drive your car in cold weather). If ambient temperature conditions allow it you can even switch to Mobil 1 5w-50 oil (not a typo for 15w-50!).
Hehehe I just had to go there!!
actually I did some more googling of the castrol syntec last night and I found out mobil and castrol sued each other as castrol use other methods to make their oil and mobil argued it wasn't synthetic by their definition.
However castrol won...
I'm not an oil nerd, I think I'll just use Mobil 1 5W40 next time...
One general comment, and that is that Porsche had to pick a "one size fits all" oil to meet emissions, foremost, then rated fuel economy, and lastly engine reliability. To meet the reliability part of the equation, you have to use a high quality synthetic if you are going to use an oil such as 0W40. I am sure that's why Porsche brands their own oil. It is more than just a revenue stream. Attached is a link with an interesting write-up on oil with some science behind it. After reading it, you can see why it is so important to use a high quality synthetic oil if you run 0W40 or 5W40. An oil such as 15W50 is more forgiving and can be run for a longer period of time, but you may not meet emissions and it may hurt mileage slightly.
http://www.kewengineering.co.uk/Auto...#_Toc240461893
Porsche doesn't brand any oil. It approves a number of oils and the oil manufacturer then adds the Porsche "A40" tag to the oil label along with probably the tag from VW, Mercedes-Benz, BMW, etc.
A 15w-50 oil will affect mileage. Some owners of the air-cooled models have admitted this to me but they stick with the oil due mainly to habit. Have to point out that the oil affects mileage because it is "thicker" and this means more molecular friction and this results in more heat. Thus the oil runs hotter the engine runs hotter than it would with 5w-50 or 0w-40. There's fuel economy that plays a role in oil selection but there's a good reason besides better fuel economy to not run 15w-50 and that's the extra heat it that results from its usage.
The 15w and the 50 might also be partially obtained by additives and these additives break down over time and at this point the oil is no better than 5w-40 oil anyhow. Additives compromise a good precentage of the weight of a bottle of oil and an oil with lots of addtives contains less *oil* than oil without lots of additives. So if one is running an oil with say 10% of its weight consisting of additives, out of 9 quarts of "oil" in the engine there is only 8.1 quarts of actual oil in the engine the rest is additives.
Mobil 15w-50 contains 10 to 20% hydrogenated 1-decene homopolymer 68037-01-4 which is used in among other things body lotion.
http://ec.europa.eu/growth/tools-dat...ls_v2&id=76642
Body lotion? Sheesh. This conjures up several observations, any of which would doubtless earn me a vacation.
FWIW, I'm not an oil nerd either. I've been using Motul 8100 5w40 for the past few years and will likely continue to do so. Seems to be good stuff and the price through Amazon Prime isn't ridiculous.
OP: A bit off topic, but I assume you've got the LN spin-on filter adapter? If not, I would strongly recommend it. IMO, at least as important as oil selection.
