OK.........seriously......I've been getting at least 1-2 mpg better average per tank on my weekend beach trips. The trick....a 9'4" surfboard hanging over the tailgate! I swear it does something! About 2ft of it hang over the top, and it's strapped to the tailgate.....at an angle coming up from the front of the bed. It must have some positive affect on aerodynamics. Anybody got a wind tunnel?