have 02 ford crew cab 1 ton, hau 40' fifth wheel toy hauler that weighs in around 14000 lbs fully loaded and i get 7-8 mpg. Dropped in 4" exhaust, edge programmer, banks trans command, edge juice with attitude and lcd screen with gauges. Done all this and havent hauled since, snowing and very icey, give you update when I do haul for the first time, truck does haul butt