Yeah: I'm willing to go side by side with the same load with anyone with a Hemi Truck. They all get great mileage until you go on a trip with them, then something always goes wrong and the truck is only getting half what it usually does.
My brother just bought a 13 Hemi and hauled a camper trailer 400 miles home with it. (18,000 miles on the Hemi though) My 05 Cummins uses just a bit more than half the fuel to do the same trip with a heavier load. Empty they're getting closer though.

Sheldon