My friend and I checked in the owner's manual and it simply refers to a list of factory recommended. No list was in the car. I mentioned the German Castrol Syntec since it has MB approvals. Do you think this is good? It looks like this 3.2 liter machine uses 7.5 liters. I figure with that large a sump, she's good for one year or 12,000 km easily. What do you think?