Mobil 1 is not your best synthetic for MB diesels. I would suggest using Mobil's Delvac One which is a great synthetic oil formulated for diesels. Also, if you do change from dino to synthetic you probably will notice some leakage in the process, as some other members have denoted.

One other suggestion for those with 100K plus miles on their MB diesels who plan on making the change over to synthetic. . The synthetic will remove a large amount old dino deposits when you go to the synthetic. Run the first synthetic 1500 miles then change the oil. It probably would be advisable to change the second early as well to help flush out the old build-up. Once you have done this then go to the recommended change interval for your synthetic.

If you don't want to use Mobil's Delvac One, then some other good synthetics are as follows:
Delo 400
Amsoil Series 3000

I am sure there are other good one's, but these are formulated for diesels. Good luck. Johnny