We just started running a new 08' Chevy 3500, crew cab, dually, 4x4, Duramax/Allison, about a month ago. We hadn't run a Duramx for about the past five years, as we have been running Dodge's since about 03'. I sent Dad to Mississippi two weeks ago with our 48' stepdeck to pick up two new 08' Dodge 2500 quad cab short bed, 4x4, Diesel's, and on the return trip he averaged 7.5 mpg. I sent him to Chicago last week for the same kind of truck except only one of them instead of two, it was really windy and that trip only yielded 6.5 mpg. I am not bashing the Chevy, as the 07' Dodge we just got rid of was only doing 1-1.5 mpg better than this Chevy. With the cost for the diesel option new being between $6,000-$7,000 depending on manufacturers, and diesel over $4.00 in some areas, a diesel just does not pencil out for most people, not everybody, but a lot of them. My new diesel truck sales are down by nearly 50% from a year ago, and gas is up almost 40%. Figure it out.