Originally Posted by kiwi29
I tried to look it up on the castrol website when I first got the car and I was extremely confused also, I didn't know why it didn't have a number on the website but the cap says "castrol."
So should I stick with mobil1 0w-40?
All will perform essentially the same in the end. Go with whichever is cheapest.
On side not I was told that in the past former Benz engineers collaborate with BMW on engine design and they use Castrol oils in that design process. Don't confuse this to mean the engines are designed to run on Castrol.