Well my friend, last time I was in Cleveland, it was so windy, that perhaps you aught to take something, to keep your insides warm.
Now there is a lot written around the world, about which oils MB use, and it varies from area to area.
However I agree that Mobil 1, and Castrol synthetic oils, are just not good enough. We run a OM612 engine in a ML270, In the Freight liner Sprinter, it is known as a MBE600,great engine, but as for getting a straight answer about oils, I can understand your confusion.
The official answer, is that when the OM612 engines are shipped ex Germany, they are filled with Fuchs EM530DC, which is used and I quote " during the initual running period". This in itself is very confusing, because how long is the running period. ML270'S here can run up to 16,000 miles depending, on the duty cycle.
We will drop the oil, and change filter at 6000 miles, because Fuchs here cannot tell me the life of the initual fill oil at this time.
There are three sheets on MB approved oil, 229.1 and 229.3 which are issued, and 229.5 which will shortly come out.
The Fuchs approved oils, that are available on this market, is Fuch Titan Inic MC, also known as Ultra MC 10W40, which is a heavy duty oil, mainly sold into Kenworth sized units, but is suitable for light diesel engines. It is a CH4/CF4/A3
The other one which is sold here, is Fuchs Titan Supersyn SL, it is a fuel synthetic oil, with a weight of 5W50. This is the oil that we use, because it is clearly a better oil. It conforms to ACEA E3/B3/A3, which is the european version of CH4. The MC 10W40 whilst synthetic, is not a full synthetic oil, a bit like Castrol blending I suspect.
Under normal circumstances, I would have continued my practice, of using Mobile 1 trisynthetic, but I note with concern, that since Mobil lost the court case, against Castrol, they have been playing with the formalae.
Believing that oil is the cheapest thing you put in the car, I decided that I would not move away from the Factory oils. The 5W50 and 10W40 will do the job here, where temperatures range from 5 to 45 degrees centergrade.
If you cannot obtain the temperature range chart, please indicate to me your temperature range, and I will exact them from my copy. If you have access to a fax, I can fax the whole sheet to you.
By the way, the main reason that MB went to synthetic oils, was to stop the problem of ring sticking, which was causing high oil consumption, all the other benefits were a bonus.
In conclusion, if I was in the USA, I would not use Mobil 1, or Castrol, and could be using AMSOL.
I do not know if Fuch is a well known brand in the USA, but they do for example, supply John Deere, with their own branded oils.
Let me know if I can be of more help.
Col Tigwell Downunder