best oil for e36 m3?

1998 M3 convertible S52US engine, driven in Southern Arizona (summer max temps typically 115 F)

Handbook says 15w-40 non-synthetic (5w-30 in low temp climates) one Dealer says 20w-50, synthethic OK another dealer says 15w-40 non-synth

local Autozone parts store stocks 15w-40 but only "for diesel engines".

I'm confused - I trust the handbook, but the thought of pouring oil from a bottle which says "for diesel engines" on the label, understandably gives pause for thought.

Comments please.

Reply to
mcquarrie
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Mobil-1 15W-50 full synthetic. And your local autozone will have it in stock. Comes with a gold cap now (used to be red) - and is called an "extended mileage" oil. I'd suggest changing it every 6-7,000 miles given the temps it will see. If you want to know exactly when to change it - drain some out and have it analyzed.

Or you could use BMW Synthetic, which is a 5W-30. I suspect given your temps that might be a bit on the thin side, but it works well as a winter oil in the S52 engine in the eastern parts of the US.

Avoid the dealer telling you "non-synthetic" - and diesel rated oil is generally an excellent oil with a better base oil than oils just rated for auto use. The peak loads on bearings in a diesel engine are much higher than auto engines, so the oil has to be very good to keep the oil film in place protecting against metal-to-metal contact. There are some good diesel rated oils to be found if you look at Mobil Delvac oils.. they come in both standard and synthetics.

Your S52 engine will use 7 quarts of oil. I'd suggest getting the BMW filters - they work well (as they should) and they come with all the seals and crush washers you need to replace them. MANN is another good filter brand, and sometimes you can find these at autoparts stores. Avoid Purolator - the ones I've seen in Autozone were made in India, and I had a BAD experience with one of these where it did not meet specifications and oil was bypassing it.

HTH

Reply to
admin

Provided the viscosity is right, I woudn't worry about "for diesel engines" with the oil...diesels run at higher pressure and load than gasoline engines, so I imagine the diesel is harder on the oil. If it can stand up to a diesel, I think it would be just fine in a gasoline engine.

The only thing I'd be concerned about is if there are any wierd additives in it that your BMW might not get along with, but it should say if there are any special additives on the bottle.

Tom.

Reply to
Tom Sanderson

I would not recommend any xxW-50 weight oil in any engine that lives at the high rpms that an M3 engine does. Ask any oil physicist and they will tell you that this is one of the most common misconceptions about oil weights, ie that if a 40 weight oil is good a 50 must be better...

The correct Mobil 1 oil to use in the S52 engine is 0W40. It is the only one sanctioned for use by BMW long life 01 standard. It is *not* one of the Extended Performance line.

If you want to use a different oil (non-sanctioned) you should use a full synthetic xxW-40 in summer and can go to a xxW-30 in winter. The xxW part is not as significant to your engine as it only represents the oil's viscosity when the engine and oil are cold. And hopefully you don't rev the bajeebers out of that fine engine when its cold, now do you?

A good alternative oil that I have found recently is the Shell Rotella T Full Synthetic 5W40. It is intended for use in diesel engines. I'm using it in my motorcycles (ducati and bmw), which is a very tough environment for an oil. High rpm, air (oil) cooled, doubles as gear oil in the duc. I would not hesitate to use that except it is not "approved" by BMW so if you have a warranty...

Reply to
Fred W

Fred - sorta difficult to explain that the BMW E46/M3 S54 engine REQUIRES 10W-60 oil isn't it? You might ask your oil "physicist" how that works and why BMW did that.

I seem to detect some misunderstanding on your part on how multi-viscosity oils work. You would only see the "50" viscosity under severe conditions - which this owners engine might see given where they're driving it. In those cases - the heavier weight of the oil will help to protect the wear parts by providing the oil wedge between them when the clearances in the engine start to widen. A thinner oil may not.

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has lots of info you might find useful, or not. Depends on how closed your mind is.

BTW - the S52US engine is really just a tarted up and larger displacement of the very familiar M50 series engines. The redline is not significantly higher than a standard M50. Nice engine, but it really doesn't have any requirements that a "normal" BMW I-6 engine wouldn't have.

The S54 engine (which requires 10W-60) is a different beast entirely - the real "euro" engine finally here in the US - with an 8,000 RPM redline, solid lifters, oil cooling of the piston skirts and all that good stuff, allowing it to make 333HP out of 3.2L almost 100HP more than the S52US engine got from the same displacement.

It meets the modified standards BMW issued to help meet corporate fuel economy standards. That doesn't make it a good oil. If you hang out on any E36/M3 forum, you'll hear how people using this particular oil seem to experience Vanos problems. Typically using the 15W-50 solves the problem.

Wait - I thought you didn't recommend Mobil1 15W-50 since it wasn't approved by BMW.... what's this with going against BMW recommendations?

FWIW - I use Mobil-1 15W-50 in my real BMW (2 wheeled one) - have been for a long long time and it is running just fine.

Reply to
admin

Thanks for the replies, but I'm still a bit confused. This happens regularly when I ask about oil...

the candidates are

admin choice #1 15w-50 full synthetic #2 5w-30

fred w #3 0w40 #4 5w40

see my point?

anyone else like to toss their hat in the ring?

Reply to
mcquarrie

Thanks for the replies, but I'm still a bit confused. This happens regularly when I ask about oil...

the candidates are

admin choice #1 15w-50 full synthetic #2 5w-30

fred w #3 0w40 #4 5w40

see my point?

anyone else like to toss their hat in the ring?

Reply to
mcquarrie

0W-40 Mobile 1 oil

It is a synthetic oil derived from dinosaur oil. It is not a true synthetic, but that's good. You aren't in a race car. You have 6 cylinders.

RedLine and Royal Purple and others are true synthetic oils.

The Mobile 1 and other brands that say full synthetic are not. The 7500 mile rated oils that the fella above is talking about are synthetic derived from dinosaur oil, but with additives to make the seals swell up so it doesn't leak. Synthetic is purely made in a lab. It is not a derivative of dead animals or whale blubber. The 7500 full synthetic oil "high mileage" is useful for cars that are crap- or are in crap condition.

If you don't have leaky valves or seals then it is not useful. In which case you would want the standard commodity derivative synthetic at 0w-40 weight. This is the oil that bimmer enthusiasts swear by.

If you do have problems with oil leaking, then it's a hardware issue and needs to be fixed. You will risk seeping oil with true synthetics if the seals and valves are not in perfect order. The mobil 1 synthetic or dinosaur oil are not as molecularly thin as true synth's and therefore do not seep through your seals as readily.

I am not familiar with using diesel oil in a gasoline engine or picking my oils based on motorcycle wear. The correlation doesn't make since to me. If you enjoy the chewbacca defensive strategy, then by all means get 0w-60 synthetic oil with additives for flavor. Like everything else, it's the right tool for the job. Don't get creative. Guys with half a million miles on their bmw's use mobil 1 0w-40 with standard Mann or Bosch filters. Best of luck to you.

And that's my hat.

ER

Reply to
Enoch Root

I cannot speak to the S54 engine design, but if the engineers designed it to use a 60 weight oil then that is what you should use. But the S52 was not designed for that.

Actually, it has nothing to do with severity and everything to do with temperature. But maybe that is what you meant by severe?

I don't think I have any misunderstanding, but maybe you do? The 50 in xxW-50 means that at full operating temperature it will behave like a straight-weight 50 weight oil does. The first number is what straight weight oil it will behave like when cold.

Depending on engine design, bearing tolerances, bearing material, etc, the exact opposite may also be true, otherwise why wouldn't we just use the thickest oil we could get?

My mind is not closed on this at all and I was already aware of this web site. But I do not see anything on that web site that supports your position that (paraphrasing) thicker oil is "better".

I really did not just make this stuff up, and am really only paraphrasing what I have learned from those more knowledgeable than myself. You may want to peruse a discussion that took place on the ducati monster forum, link provided below. It really has influenced my opinions on much of this oil viscosity stuff. It is kind of long but worth wading through in my opinion. Georgecls is a very knowledgeable guy.

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Exactly. And I don't think using a 50 weight oil in an M50/52 engine is such a great idea either except under very high ambient temperatures (desert, death valley, etc.) or worn engines.

As a point of reference, one of my other (non-BMW) cars is an '03 SAAB

9-3 Vector with a 2.0 liter engine making 210HP. That's actually a slightly higher HP to displacement ratio than the exotic S54 engine. Granted, it does so with the magic of forced induction and at lower RPMs, but it uses only Mobil 1 0W40 oil per the manufacturers *requirement*. Anything else voids the warranty.

I disagree. If they wanted to improve the fuel economy averages they would have gone to a lower weight oil (xxW-30 or xxW-20). Having an oil where the first number is smaller does not greatly impact the viscosity at operating temperature, which is where the fuel mileage is determined .

Well... I have actually experienced the vanos "problem" first-hand on my 1995 325i M50 single vanos engine.

It is not a "problem" so much as the vanos just gets noisy and the valve timing advance comes into question. So, running a thicker oil, which has the effect of increasing oil pressure in a worn engine with increased bearing tolerances, does in fact quiet down the vanos. But my experience was when using 5W30 Mobil 1, not 0W40, which is a significantly heavier oil at operating temps.

No, I think that you misunderstood me. The basis of my not recommending Mobil 1 15W-50 is that it is a 50 weight oil and is not optimum for that engine. The fact that BMW specifies and sanctions only the use of Mobile 1 0W-40 or their own full synthetic oil for those engines tells me the engine was designed to operate on that weight oil. Given that I would say that other 40 weight synthetic oils would/could/should be used also.

Yeah, and that is probably a good choice for that application.

Hey, lets face it, we aren't talking day and night here, just varying shades of dusk. I'm sure we could run with either of our recommendations and, given fairly frequent oil changes, our engines would both run long and happy lives. But then what would we talk about on usenet? ;-)

Reply to
Fred W

Ah... welcome to usenet. Place of the never-ending oil discussions...

Reply to
Fred W

I have seen this before on the internet and I'm pretty sure people are confusing Mobil 1 and Castrol Syntec. I'm pretty sure that it is the Castrol that is the synthetic made from cracked mineral oil. Mobil 1 is true synthetic (whatever that means)

Philosophical question: What is synthetic? Is it something that is man made, ie. not occurring naturally? If so, when was the last time you saw petroleum based 10W-30 oil come out of the ground?

Reply to
Fred W

No, they aren't confusing motor oils. Synthetics cost much more to produce because they aren't an extraction of anything. They are completely laboratory manufactured. There are no base components.

But, it's all semantics. It does not affect regular car owners. Those nascar engine's with enough horsepower to raise a small building- they need that kind of oil. We don't.

And at the consumer level, yes it is a point of view based on semantics leading towards philosophy to an extent. The synthetic derivatives don't leave nearly the same kind of breakdown as pure dinosaur oils. So everyone comes out ahead.

I understand using different weight oils depending on expansion due to persistent heat and breakdown. That applies to low ceiling thermal tolerance oils like dinosaur oil. But synthetic based oils don't have the same tolerances as regular oil. You can safely not give a shit about weight with derived synthetics and even more so with pure synthetics.

So, in short, if it ain't broke don't fix it. Use the recommended synthetic oil because it doesn't break down like regular oil. And your engine will be happy and clean and you won't get stuck in the crackhead part of town with your nice european car.

ER

Reply to
Enoch Root

According to Wikipedia, synthetic oil comes from a reaction of CO, CO2 and methane. Methane is the primary constituent of natural gas, which is extracted from the ground.

Reply to
Nobody Important

Now who would want to igore a twenty five year old tradition? I mean really...

Reply to
Richard Sexton

I have read enough discussions previously, that I should have known I wouldn't get a single answer.

Thanks all the same, but I'm going with the handbook - BMW 15W-40 non-synthetic. Also recommended by a BMW dealer. $24 for 8 quarts isn't too bad either.

Reply to
mcquarrie

My car came with non-synthetic recommendation (MB 190E 2.0 l, 1993) but I switched to Mobil 1 at one stage (even tho' the dealer wanted to continue with traditional oil), the type now recommended for many Mercs. I think this would be especially wise now, given the pounding the engine gets (a few short city engines every week). I have about 72 000 miles on the clock now.

DAS

For direct contact replace nospam with schmetterling

Reply to
Dori A Schmetterling

Eh? Explain. They come out of the air?

Reply to
Dave Plowman (News)

Well, you certainly got a variety of answers. What you need is another one

- especially since it will be controversial.

Anyway, the owner's manual recommendation for your car is the same as the owner's manual recommendation for my 97 328. I've been using Castrol

15W-40 now for 128K in my engine. Live in Sacramento and drive all the time (hot summers included) to Las Vegas, Phoenix and Tucson. Engine purrs like a little kitten. Believe me, if oil were going to break down, mine surely would have done it on some of the hot drives up I-5 at 115 deg in the shade and the AC going full blast. Here's what I've found about these oils.

Many 15W-40 oils are rated for LIGHT diesel (automotive) AND heavy duty gasoline engines. Read the label completely - it will give all the standards. Be careful, there are HEAVY DUTY diesel and LIGHT duty diesel - you need to read the label.

For example I just put a new batch of Castol GTX diesel 15W-40 in my car. On the bottle are the following. API service ratings CI-4, CH-4, CG-4, CF-4, CF/SL SJ - PLUS meets Mercedes-Benz 228.1 AND ILSAC GF-3 for API certified GASOLINE engine oils. (Note SL, SJ ratings are gasoline engine)

Oil viscosity is important for lots of things - oil flow rate for cooling, bearing film strength, and spray patterns. In your engine are spray tubes from the crank to the pistons, for example. IT SEEMS REASONABLE to assume that obtaining the proper spray pattern and flow rate would require the correct viscosity - that's why I wouldn't consider any 30 weight or 50 weight oil in my car, as long as the temp is within the manual specs for

15W-40

With my M52 engine - I follow the service interval lights. Engine runs like a dream at 128K now. Again, I think the secret, is using the 15W-40 dino oil recommended in the manual. Here are few reasons

  1. These oils are diesel rated - more antiwear additives etc.
  2. My oil is still quite clean even at the 7500-8000 mile intervals that the service indicator comes up with.
  3. I use the Castrol, and this oil clings very well to the engine parts even after the car has been sitting for over a week. Absolutely no tappet noise, or whatever upon startup.
  4. I think it extremely important to have the recommended viscosity (40 weight) as this affects the oil spray pattern to the pistons, across the camshaft etc.
  5. Most important, the single step Vanos on these engines appears to be more reliable than the later, continuously variable, dual vanos, as it apparently does not need as high a pressure for operation. Mine works seamlessly, and I think much of the credit goes to using the 15W-40 oil. Again, these oils are diesel rated, and when you pour it in, you'll notice it is quite different from either 10W-30, or 20W-50 oils rated for gasoline engines only. I just

think the clearances and vanos system on these engines are designed for this oil. Using it (plus premium gas) just makes the engine emit a mesmerizing soft purr between 4 and 5K in 2nd and 3rd gear.

These 15W-40 oils just seem matched to clearances etc. in the engine. I'm going by the book, but I suspect there will be lots of people here saying you'd be better with synthetic, or different weights.

I dunno - how can I trust the BMW engineers to have done such a fabulous job in recommending the correct oil for their fabulous engine, but then notice that everytime I climb into the car at nighttime, there is no illumination for the stupid red, blue air temp control knob on the dash AC vent, so I always have to hunt for it. Truly boggles the mind.

Frank

Reply to
Raybender

"Dave Plowman (News)" wrote

There are no base components that are oils. Obviously, it has to come from something.

All non-synthetic oils are some combination of refining/filtering/additives of existing oil (almost always some petroleum fraction).

Synthetics are manufatured from feedstocks which aren't oil. They're much "cleaner" compositions than petroleum-derived oils.

Tom.

Reply to
Tom Sanderson

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