US Patent 10081397 Fuel efficiency of road vehicles

A road haulage trailer (810) has tail deflectors (896) for directing air flow to a region (829) behind the trailer during forward movement of the trailer. The tail deflectors (896) protrude from the sides (822) of the trailer and extend beyond the rear end (825) of the trailer. The deflectors (896) define a guide surface that is angled or curved towards a region (829) behind the rear end (825) of the trailer (810) and is a continuation of the side (22) of the trailer.