Oil question...

So i have an E36, what grade of oil do you recommend? I used 15w50 in my E30.

what engine ?

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A physics truck just turned over outside. There's physics everywhere!

Oh right, I guess if I had a M3 it would be a different engine, I have a 95 325iS, so whatever engine that is, M50? I also have 189,000 km, but no leaks.



Edited 1 time(s). Last edit at 01/09/2009 10:31AM by Andrew.

I'm thinking 10w40? what do ya'll think about that? The thing is, is I have a nice big jug of mobil 1 full synthetic 15w50, maybe I could use that in the summer? I do use a block heater religiously here, but what happens if I park somewhere I can't plug the car in right?

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Andrew
I'm thinking 10w40? what do ya'll think about that? The thing is, is I have a nice big jug of mobil 1 full synthetic 15w50, maybe I could use that in the summer? I do use a block heater religiously here, but what happens if I park somewhere I can't plug the car in right?

Not knowing what the manual for your car specs, I can't make any recommendations.

But the difference between 10w40 and 15w50 in a synthetic should cause you no concern in cold conditions; even if you live in Siberia or Montreal.

Check on one of the E36 forums to be sure what BMW recommends, then use that. The oils for the E30 and the E36 are likely to be different as the M50 engine is supposedly built to tighter specs than the M20.

Ok, thanks Peter, I'm sure I could find out what it recommends in my owner's manual.

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Andrew
Ok, thanks Peter, I'm sure I could find out what it recommends in my owner's manual.

There should be a chart showing which oils to use for various temperature ranges.
Follow the manual and not what the BMW parts counter guy says; unless they are the same

BMW recommended me 5w40 for the M50 engine 2 years ago. This year they recommended 15w40 (they said the engine is old so it's worn out so it needs thicker oil). I'm still going with 5w40, both winter and summer. We have 45 Celsius in the summer and -15 in the winter (-20 if i go to the mountain). I never had any problem, other than some noise when starting after a winter night, which i believe is normal due to the age of the hidraulic tappets.

This winter I tried 15w40 (because of some idiotic reason in my head, that was hearing strange noises), there's no difference at all.

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A physics truck just turned over outside. There's physics everywhere!

Switching to a 15W40 oil from a 5W40 because 'the engine is older and needs thicker oil' is nonsense. Both oils, especially if they are synthetic, act as a 40 oil when at normal engine temperatures. The 15W oil is thicker at cold start temperatures and actually offers less engine protection due to its lower flowing capabilities at those temperatures.

Stick with the 5W40 synthetic or switch to a 5W50 synthetic, year round.

Salut, Bob P.

i told them the same thing, but they didn't seem to care :nerd:

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A physics truck just turned over outside. There's physics everywhere!

They don't...they aren't hired for their intelligence

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Bob P 325is 88
Switching to a 15W40 oil from a 5W40 because 'the engine is older and needs thicker oil' is nonsense. Both oils, especially if they are synthetic, act as a 40 oil when at normal engine temperatures. The 15W oil is thicker at cold start temperatures and actually offers less engine protection due to its lower flowing capabilities at those temperatures.

Stick with the 5W40 synthetic or switch to a 5W50 synthetic, year round.

Salut, Bob P.

if this is the case, then does that mean something like a 0w50 is even better? I am about to change the oil in my S52, and I am pretty sure 10w40 is in there now, but the coldest it gets here is maybe 20F and the hottest it gets is 100F, so I'm having a hard time believing that 5w50 is going to be any better than 10w30 or something. should I go for the Xw50?

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daniel

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Bob P 325is 88
Switching to a 15W40 oil from a 5W40 because 'the engine is older and needs thicker oil' is nonsense. Both oils, especially if they are synthetic, act as a 40 oil when at normal engine temperatures. The 15W oil is thicker at cold start temperatures and actually offers less engine protection due to its lower flowing capabilities at those temperatures.

Stick with the 5W40 synthetic or switch to a 5W50 synthetic, year round.

Salut, Bob P.

if this is the case, then does that mean something like a 0w50 is even better? I am about to change the oil in my S52, and I am pretty sure 10w40 is in there now, but the coldest it gets here is maybe 20F and the hottest it gets is 100F, so I'm having a hard time believing that 5w50 is going to be any better than 10w30 or something. should I go for the Xw50?

If you don't want to listen to the words from one who knows, fill your engine with whatever the fan boys recommend...but don't be surprised if you don't get the kind of mileage Bob is getting from his M20

Danial,

If the lowest temperature that you are going to see is only 20F, then i would suggest that the present 10W40 synthetic is fine. Personnally, for those conditions I would go for a 15W50 synthetic. Presently, I run 5W50 year round in my M20 of 666,666 kms(love that number) and I have experienced temperatures as low as -35C, with no starting problems. I haven't seen a 0W50 synthetic, but that would be a good choice for extreme arctic racing conditions (-40F and lower) when one wouldn't have the luxury of keeping the engine running or oil warm between trips. I have seen -5W20 synthetics, however

Salut, Bob p.

Daniel doesn't have the M20 in his car. I don't know for sure but I think the M50/52 were built with tighter tolerances and may have originally come with a 5W30 oil in them.
Wouldn't the xW50 be a bit on the heavy side or do you think it's being synthetic will work just as well?

Bob,

What's your take on this ...
[forums.bimmerforums.com]

You are probably correct for the s52 engine, unless it is showing signs of burning or passing oil. A 5W30 synthetic should still be alright, but if using/losing oil, a switch to 5W40-50 should do the trick.

Salut, Bob p.

Excellent information, but sometimes difficult to follow. My take on that info for our engines (pre-vanos etc"), is that Mobil 1 0W40 does very well and so would a 15W50. I don't see any information on the 5W50, but I suspect that it is a group IV and would suit me fine, as I have been recommending.
The oil recommendations and standards have really changed with the arrival of the hydraulically powered variable cam systems and close tolerance engines, necessitating 'thin' but high shear resisitance oils. Hence the need for a low temperature flowing oil (0W) and high shear resistance in tight tolerances at operating temperatures (30-40) oil, that a 0W40 will give.
Although shortening the change interval from BMW's schedule can do no harm, I don't think that their interval is 'too long'. It is about the interval that I have been using, btw.

There is a lot of 'marketing' involved in the specifications of oil and car manufacturing requirements (they make money on 'their' oil), so until the warranty period is over, I would follow the manufacturer's requirements and then switch to 'my' optimum regime!

Salut, Bob P.