Elaboration on the '07 MY diesel. It's a V-6 that's being sold in Europe
now; it has about 30% to 35% better fuel economy than the 3.5 L V-6 gas
engine (UK figures for E-Class).
The M-B diesels being sold in the USA today (other than Calif. and New
England where no M-B diesels are sold) are older, straight sixes that
are good motors but have been superceded by the cleaner V-6 cdi which is
supposed to be a 50 state engine.