i bought a 05 denali 2 weeks ago. It is awd. not sure if all of them are or not. Today i averaged out the mpg. It was about a 1/4 tank left. Last time i reset the tripper and did the average that way. Im averaging 10.1 mpg. Isn't that low? There aren't any mountains or big hills around me. I do mostly city driving and never take it above 2500 rpm. I drive like old lady lol I check the tire psi every other day so its not that. The truck has 130 k miles