# Retractable tailgate

1. ### Loren Booda

Why don't pickup trucks come with a tailgate designed to retract (manually) before highway driving when practicable? It seems self defeating to have such inefficient drag as from an upright tailgate. I believe that by this retraction the truck's highway consumption would increase by at least 1/2 MPG.

2. ### Danger

9,878
I'm not sure about the efficiency of that. Someone (I think that it was Mythbusters) did some tests that showed not a lot of difference in drag with the tailgate up or down. That's all that I have for now, since my memory is failing.

3. ### ank_gl

735
yes, they showed that tail gate up maintains a nice separation bubble behind the tail gate(towards the truck), and act as a boundary for incoming stream, hence reducing pressure drag