Originally Posted by Dackelone
The engine oil can be either: 0w40, 5w30, or 0w30 with BMW LL-1 for the USA and LL-4 for the Europe. The main thing to check for is the LL-1 (BMW Long Life rating) or LL4 rating. Also... you can use LL-4 rated oil in a market that requires LL-1 but not the other way around! So the guys in the USA can use a LL-4 rated oil, but the euro guys should only use LL4 rated oil.
This is one reason I buy the expensive German Castrol RS Edge 0w40 (LL-4) oil for my 135i.
do you think that I can mix 0w30 LL4 with 5w30 LL4 (1 liter to add) for my 1M