Since the GVWR of the Silverado 2500HD is so high, General Motors isn't legally required to post fuel economy figures on the window sticker. That's too bad, as it may well be a selling point. I piloted this long-bed, crew-cab, four-wheel-drive diesel monster between Howell and Alma, Michigan, averaging about 75 mph on all roads. According to the on-board computer, I averaged just above 18 mpg; a bout of city driving brought that figure to the high side of 16 mpg. That's quite impressive for such a capable machine.
Evan McCausland, Web Producer