hey guys ,,, the thread here awhile back should have included at least one link to professional studies that have shown leaving the tailgate down does nothing for your mileage, tho all the bed cover folks claim the covers help
check this and also the link from there
to this as I commented the last time this idea came up, I've noted on several occassions that I can drive the truck in pouring rain w/ cardboard boxes in the bed and they don't get wet till I stop - always was evidence to me that the wind over the truck does not swoop down and hit the tailgate to create drag
Bill
