I bet you don't drive it every day. I don't mean every day one paticular week either. Mine has to pull dual duty, toy and grocery getter.hmmmmm whats gas mileage????? on a good day with everything running as it should i get about 5-8 mpg with a 383 stroker th350 trans 2300 -2500 rpm stall 4.88 gears and 38 inch tires