Hi, I am a new member who is a bit confused about the oil weight recommended by my dealer's service manager and what is recommended in my owner's manual. The service manager has always put BMW branded oil in the engine, but recently used what he said was a "new" 5w40 oil instead of the 15w50 oil that he has used in previous oil changes.
I tried to get an explanation from BMW America without any success...the fellow I spoke with on the phone only had access to the same service info that I did and wasn't able to refer me to anyone who could tell me why the change. It seems to me that in the absence of some official service bulletin or update, that the oil specified by the engineers who developed the engine should be followed. Can anyone shed any light on this?
I tried to get an explanation from BMW America without any success...the fellow I spoke with on the phone only had access to the same service info that I did and wasn't able to refer me to anyone who could tell me why the change. It seems to me that in the absence of some official service bulletin or update, that the oil specified by the engineers who developed the engine should be followed. Can anyone shed any light on this?