Okay, I have a 2000 Chevy Silverado 2500 LS reg.cab long bed 4x4, 6.0 V8 cast iron heads, 4L80E trans and 4.10 gears. I say that because the 6.0's are mostly all aluminum, I just got the rare one I guess. The truck has 95k on the clock and a new trans with only 7k on it. I dont have a lead foot and the tire size is 265/75R16. Brakes are new, etc. I dont tow a big trailer at all, 6.5ftx10ft which weighs 880 lbs. I only have my weedwacker, edger, mower and lawn boy on it. I get maybe 5-7 mpg towing the trailer and maybe 8-10mpg with out. Mind you the plow frame is off, etc so it is a bare truck. I keep up on ALL maintenance, just did oil change, and new air filter. What I dont get is it got 14 mpg in the winter with 600-800 lbs of salt in it, the plow, tools, in 4x4, pushing snow. Now bare bones truck gets worse mileage. I dont get it. What is making this thing suck the gas down so friggin bad?? It has a slight leak in the exhaust gasket on the manifold, but it was like that in the winter. I wouldnt think that would cause it to be such a hog. Any help or ideas or anything would be appreciated. And NO I am not gonna get a new truck either.