Originally Posted By: Flying_A
Just want to add that Mobil 1 is the factory fill for many Mercedes models and the recommended in service fill is Mobil 1. There is an exclusive product made for your car called Mobil 1 5W-40 Formula M. Specifically engineered for Mercedes and available at the dealer or at a local Mobil distributor.
Good point. I forgot about this one.
With that said, I am still trying to figure out what makes this oil better than their 0w-40 for gasoline engine applications. This Formula M 5w-40 is kind of in the middle between M1 0w-40 and Formula M ESP 5w-40 when it comes to add-pack levels and TBN. I would expect the high TBN M1 0w-40 (11.8) to handle longer drain intervals better than Formula M (non-ESP) 5w-40 (TBN of 8). The only reason to consider Formula M would be if you had some sensitive emissions equipment, but if you did, then Formula M ESP would be even better.
Alas, TBN does not always tell the whole story...