Member, P500 Sport, DSC off (>900)
Join Date: Aug 2001
Location: Lake Villa IL USA
Thanked 2 Times in 2 Posts
Here in the US, the only synthetic 10w60 available is the Castrol RS, and the only place I've found to get it is at a BMW dealer. Castrol tells me there are no other retail sources for it - apparently they import it specifically for BMW. I would have no problem using Mobil 1 if it were available in 10w60 - but as far as I know it isn't, and won't be any time soon.
Given the choice between topping up with Mobil 1 and Castrol, I'd pick the Castrol because it's a closer match to what's already in the engine, but if that weren't available I'd use the Mobil 1 15w50 and I'm sure it would be just fine too.