I agree, but without additives. The same car as you too - a Mercedes E320 CDI that exceeded the EPA estimates. I would get 43 mpg at 65 mph on flat land for a car rated at 37 highway in the more optimistic era before they made the "correction" on the newer models.
Originally Posted by gulfcoastbeemer
I'm not a genius with additives, like Clark Griswold or yourself, but empirical data of my own, collected in the form of 10-years of fuel receipts for five different diesel engine vehicles, suggests fuel economy does vary with fuel source / "quality". Everyone of my diesel vehicles has regularly exceeded the EPA mileage estimates published for them. Darn if I know why.
I'm going to attribute it to the power of positive thinking -- we know it can't be a fuel additive.
Rose Castorini: I just want you to know no matter what you do, you're gonna die, just like everybody else.
Cosmo Castorini: Thank you, Rose. - Moonstruck
Last edited by Pierre Louis; 02-18-2013 at 02:01 PM.