BMW M50 5w30 oil & high mileage

[Russell]

BMW currently recommends 5w30 synthetic for the M50 engine like I have in my 95 525i with 157,000 miles. I am a bit concerned that this is too thin. Should I use a 40 or even 50 weight? TIA

 

[JustinH]

I would run a euro syn motor oil..

5w40..

Rotella T synthetic comes in a 5w40 thats a very robust oil..

 

[d00df00d]

No need to be concerned. BMW's 5w-30 syn is an awesome oil and will have no problem with your engine.

 

[nel]

I have the same year BMW e34 but as a wagon. I've had good luck with Mobil 1 10W40HM in that car. Since BMW had spec'd 20W50 non-synthetic oil for that car, I too was hesitant about using a 30 weight oil. Here's an excerpt from my most recent UOA with M1 10W40HM:

209,600 miles on engine; 7,200 miles on the oil

Copper 10
Iron 13
Chromium 1
Aluminum 4
Lead 1

The oil had a trace of water, so no viscosity was given by Butler Labs.

Having said this, I haven't had any issues with using a 30 weight synthetic in my wife's '97 328i (similar but not identical engine with nearly 100K fewer miles).

 

[Craig in Canada]

BMW 5W30 is a thicker-than-average 30 weight since it meets ACEA A3, BMW LL etc... You'll probably be fine with it. If it makes you nervous, select a 5W40 - Rotella, Amsoil AFL, Castrol Syntec...

 

[02Pilot]

FWIW, I'm running RTS in my M54.