Originally Posted by apecush
That logic is ridiculous. The addition of one quart of lower viscosity oil will impact the overall kinematic viscosity of the oil (generally around 8 quarts) a negligible amount. Consider that versus the oil pump firing air into your bearings while going around a corner.
I'll add my extra quart of non-10w60 thanks. BTW, oil analysis indicates that the oil quickly shears to a 40wt at operating temps anyway, so the overall viscosity change is even less.
By the way, the manual states that small quantities of non-oem spec make-up oil can be added without issue.
Just USE THE BMW recommended OIL! That's all I had to say to begin with......Your most likely more "Safe" with running with low oil than putting the other crap in it. I'm not saying it's going to break or blow up your engine here. I know one quart of non-10w60 isn't going to hurt but I'd rather be safe using the CORRECT oil for our high revving V8's that need the right OIL. INMHO my 70+ thousand dollar car who deserves more respect than that
So every time you run into this situation you put at least a quart of non-10w60? NO need to bash because we don't agree what to do in this situation.