[ccjohnson]

Absolute worst I have gotten was 5.25 mpg, mountain grades & pulling 20' car hauler with an F350 4x4 crew cab on it. Absolute best was 7.5 on gulf coast over a 300 mile run towing Suzuki XL7 at about 60-65 mph (before we got new tires). General average +/- 6.3 mpg no matter what we tow at about 70-75 mph. Seems to run better at 70+ mph. But have to downshift & slow down on long steep pulls due to temp.