Does a pickup truck get better milage when the tailgate is up or down?

Question

Just a curiosity question to help solve a bet.

Answer 1

Air turbulence as a result of the tail being up overcomes some of the air resistance same like the streamline shape has an effect in reducing it , in general reducing the resistance increase the over all efficiency and reducing the fuel consumption as a final result

Answer 2

Gas mileage is better with the tailgate up.  The idea is that when the tailgate is up, it creates a sort of calm bubble which reduces the aerodynamic drag on the truck, which in turn makes for better gas mileage.

Mythbusters checked this one out a couple of seasons ago.

Answer 3

mythbusters did this once and proved tailgate up was better sounds odd but thats what was said

Answer 4

Tailgate up...it creates a cushion of air in the bed of the truck which helps air flow over the truck and avoids a suction or drag effect on the back of the truck. Mythbusters did a segment on this and found it surprisingly true.

Answer 5

Up, the way wind collects in the back of a truck it is more "aero dynamic" with the tailgate up.