Wow! Thanks! I had pretty well concluded all this but some of you folks are pretty savvy and come up with reasons why factory instructions aren't quite right. I remember a 126 I picked up at the factory where they strongly cautioned me against additives of any form, yet when I got the car home, the dealer advise that the factory had approved ONE additive for the fuel, Redline.

Didn't use anything on an E350 BlueTec and don't plan to on this one. Thanks!