Q: I heard that putting the tailgate down on a pickup truck would make the vehicle achieve higher fuel mileage. Is this true?
A: This is a myth of yesteryear. While this may work on 1970’s trucks, today’s trucks are much more aerodynamic. Wind tunnel tests have shown that there is less wind resistance with the tailgate up than with it removed or down. The cabs are so streamlined that the air goes over and around the cab and then is pushed above the tailgate when driving at highway speeds. Putting the tailgate down actually increases turbulence at the rear of the vehicle. If you are looking for a better solution, put a tonneau cover on the bed. These tend to reduce drag even further on the pickup, resulting in increased fuel mileage.