[aerohead]

I did a bed deletion on the Dodge pickup and lost 2-mpg,from 18.6mpg,to 16.6mpg.Without the box behind the cab,there is no airflow support mechanism,and the flow simply separates into a horrendous turbulent wake,never to re-attach.The aeroshell,as used on Ford Motor's F-150,my D-100,and T-100,offers the lowest drag reported so far,as it allows the displaced air to better re-organize itself as it was before you came along,much like a bird,or airplane.