Abstract: A mechanism comprising of a trailer skirt for attachment beneath a lower, outer longitudinally extending edge of a trailer, containing a plurality dimples disposed upon a planar surface of the skirt, thereby improving aerodynamic efficiency. The plurality of dimples may have any number of shapes, including a variety of multi-sided polygonally shaped depressions. In one embodiment, the depressions have a plurality of frusto-spherical shaped depressions.