Abstract: In order to increase energy efficiency by reducing the drag experienced by bodies moving through a fluid medium, such as tractor-trailers, structure is incorporated in the rear surface or panel of the bodies. The structure is implemented with a multiplicity of cavities or a multiplicity of protruding regions. The cavities or protruding regions each comprise only a small portion of the total area of the rear surface and the depth or extension dimension, relative to the rear surface or panel, is small. In the case of a tractor-trailer, the rear surface structure permits convenient access to the interior of the vehicle and can be incorporated in either a rear door assembly or in a sliding rear panel assembly. The drag reduction benefits are achieved not only when the body is a tractor-trailer but also in the case of all types of land vehicles, water craft, aircraft, projectiles and the like which have a relatively flat rear surface.

Abstract: In order to increase energy efficiency by reducing the drag experienced by tractor-trailers, vans, or similar motor vehicles, structure is incorporated in the rear surface or panel of the motor vehicle. The structure is implemented with a multiplicity of cavities or a multiplicity of protruding regions. The cavities or protruding regions each comprise only a small portion of the total area of the rear surface and the depth or extension dimension, relative to the rear surface or panel, is small. The rear surface structure permits convenient access to the interior of the vehicle and can be incorporated in either a rear door assembly or in a sliding rear panel assembly.