A tail gate air diverter tarp provides a streamlined airflow across the bed of a truck to substantially reduce drag on the truck and improve gas mileage. The tail gate air diverter tarp is configured for a universal fit in a truck bed across a variety of manufacturers. The tail gate air diverter tarp has a web reinforced perimeter and a pair of cam buckles attached to the web reinforced perimeter at each corner of the tarp, with one cam buckle oriented in a lateral direction and the other cam buckle oriented in a lateral direction. A cinching strap adjustable couples selected cam buckles with a mount carried in the bed of the truck.