The answer I got from Mercedes was something like this: the FSS system works fine, but if you use dino oil, change it halfway through the FSS cycle. That was it. No explanation. So I tend to agree that there might be some flaw with the FSS system and Mercedes wants to preempt future warranty claims . I have yet to see this recommendation in writing. As far as the diesel cars go ,I was told that the engine warranty has been extended to 150,000 miles, but again I received nothing in writing from MBUSA on this matter.
There was a FSS mailer from MBUSA that, according to a service advisor was to include all of the above information as well as a discount coupon for an oil service. What I received after a series of calls was a letter stating that I should be sure to use only MB
approved products and a list of approved synthetic oils to use. Funny thing was, the last time I had an oil service at the dealer, they used dino oil! That has since been changed to synthetic.
I'll do some research on the class-action suit and post the results here or on the diesel board.