Mobil 1 0w-40, why? Seems to me that Mercedes, BMW, VW/Audi have done decades of testing and development with that brand and that viscosity. Yes I have a couple of them ferrin cars and use only that with no bad results......so far wink I even use it in several big displacement V-Twin motorcycles and one 1000cc 4-cylinder "flying brick" also with good or is that no bad results. wink