Oil chart from the E30 owners manual.

[DiamondSchwartz]

Here's a pic for the oil BMW recommends for the E30.

[ELVA164]

Thanks for sharing, but grain of salt folks. See that "special oils" asterisk on the side? That refers to the first widely available synthetic blends. These days it's best to either check with BMW for their recommendation (Mobil 1 0W-40 for the M20), read one of the threads on these forums filled with equal parts helpful info and silly back-and-forth discussion, or read up on how oils work and what you do or do not need for your particular engine, mileage, and climate.

[jlevie]

You can see my opinion on engine oil for an M20 in http://www.r3vlimited.com/board/show...1&postcount=10

[ELVA164]

Interesting info there about the gearbox tags!

[estoguy]

Definitely out of date considering today's oil.

Personally, I'm running synthetic in mine - Castrol Edge 5w50 - this stuff has a higher zinc package. Most of my driving is at speeds above 80 km/h (50 mph). My change interval is between 10-12000 km (by the SI lights, I usually have 1 or 2 green ones left when I do change). I've had some oil analysis done, and it certainly doesn't seem to hurting the engine.

[ericneet]

Mobile 0 40w is a terrible idea. It clearly says the minimum weight should be 15w unless you live in Barrow, Alaska. My m20 is so much happier with 15/50

[nando]

Mobile 0 40w is a terrible idea. It clearly says the minimum weight should be 15w unless you live in Barrow, Alaska. My m20 is so much happier with 15/50

0w refers to the cold pouring ability, not to the level of engine protection. a 0w will be better at any temp for cold starts, not just at freezing temperatures. The reason the manual recommends a 15w is because it wasn't possible to have oils with such a wide spread back in the 1980s without diluting it with additives. Now we have things like 10w60s that were physically impossible to produce back then. same with 0w40, it didn't exist because the technology wasn't there. Compare that to what was common in the late 80s - 10W30 or 20w50.

[e30rik]

So should I not use 20w-50 in my M20?

[nando]

you can but why? there are better oils to use these days that provide the same protection but flow much better when cold, such as 15w50, 5w40 and 0w40.

I found a 10w50 Mobil 1 once in Canada but never saw it again.. that would be a perfect oil to run IMO, but it doesn't seem to exist (and I could have been crazy in the first place).

[ELVA164]

As a point of reference, I used to use Mobil 1 15W-50 in my E30 (and used it in my 2002). It's a good oil, but when I switched to the 0W-40 the cold crank speed was significantly improved and it even reduced driveline lash when lifting off throttle. If it's hot all year I'd say the 15W-50 is fine, but if you have cold winters I think the 0W-40 is a good all-year oil. Mobil is very open about the contents of their oils and both of these weights have sufficient ZDDP.


And to nip it in the bud, there is no extra valvetrain noise and no extra leaking with the 0W-40.

[jeffnhiscars]

you can but why? there are better oils to use these days that provide the same protection but flow much better when cold, such as 15w50, 5w40 and 0w40.

I found a 10w50 Mobil 1 once in Canada but never saw it again.. that would be a perfect oil to run IMO, but it doesn't seem to exist (and I could have been crazy in the first place).

I get 15-50 at Walmart whenever I need it for $23 a jug. If you read Mobile's chart this is the only grade that has sufficient zddp

[ELVA164]

I get 15-50 at Walmart whenever I need it for $23 a jug. If you read Mobile's chart this is the only grade that has sufficient zddp

1000/1100ppm in the 0W-40 is sufficient, if not comfortable for some people.

[digger]

years and years ago mobil 1 5w-50 was popular now its nla in these parts

seems to have 1000ppm zddp which probably ok for a stock street engine

http://www.mobil.com/USA-English/Lubes/PDS/GLXXENPVLMOMobil1_5W-50.aspx

i now use a 10w-50 they are pretty common in these parts, you can even get a 5w-50, 0w-50

http://www.penriteoil.com.au/products.php?id_categ=1&id_brand=4&id_products=281

http://www.penriteoil.com.au/pis_pdfs/SIN%20Engine%20Oil%200%20JAN%202010.pdf

[LowR3V'in]

Isn't there a test you can do with oil pressure seeing what oil your engine likes?
Something scientific. I like revving my engine to 7k making allot of HP is 0w.40 a good idea?

[digger]

yeah you can determine the correct grade based on oil temp and pressure data. If its a warm hot summer you are probably going to want xxw-50. IMO with a preference for the xx to be as low as possible. when its colder xxw-40 should be fine.

if you add a pressure gauge and the pressure is good when the engine oil as hot as it gets with your driving style and conditions then the viscosity is fine