Just got back from trip to FL. Purchased a retractable tonneau cover before leaving. Loaded truck with essentials for a family of six. On the way over I averaged 15mpg but I was going 80mph. That is better than the 12mpg I was averaging in city. On the way back I drove the speed limit which averaged about 70mph and my mpg went up to 17
. I have not driven the truck much to see my mpg gains in city driving yet. But this is better mpg average than I was getting with my 01 Tahoe Lt with 20" rims and flowmaster exhaust (15mpg highway). By the way my 250 kingrach also has 20" wheels.