Oil is really interesting. If you want to find out all about it go to www.bobisthoilguy.com. It is a forum of oil FREAKS! <img src="/forums/images/graemlins/zombie.gif" alt="" /> (I mean that in a good way).

Synthetic vs Dino is the age old question and there is no final consensus. I personally am sold on Synthetic. Dino cannot match Synthetics flowability at cold startup.

As far as fuel dilution, condensation and the other crap in the oil. As long as you drive some longer trips all of that will evaporate. Engine Acids? - the synthetics have a higher ability to nuetralize acids than most dino oils. Engine wear particles? - they are suspended by the additives in the oil.

If I had that MB I would of course only use the MB recommended synthetic, and I would change the oil and filter when the oil life indicator reaches 25%.