I do know the 0W40 is what is recommended in the USA, wallymart has it on sale now, The rotella T-6 is also a low ash oil and is API SM (gasoline) grade so it wont hurt it if I use it for about 5000 or 6000 miles - most European fleets running this engine use such oils with no side effects. I'll pick up two bottles of the mobil 1 and keep it stashed for next use. btw the vicsosity chart for this engine also has 20W50 oils - and it falls right in place for the climate Im in right now, its 85 even at midnight - usually 100 all day long.
anyway, I did the paper towel blotch test, the oil floating in the coolant is bleeding brown and so is my ATF (I think its genuine MB 722.6 ATF - which is supposed to be straw colored). I will try to get a sample sent over for diagnosis to what it is actually and install a dedicated atf cooler just in case - because I dont want engine coolant to end up in the trans.
