Wheel covers are inserted into the wheel of all tires to streamline the airflow around the tires and can be used on all six wheel ends of a tandem axle tractor.
A variety of manufacturers produce aerodynamic wheel covers, and small benefits can be achieved by using them as part of an overall fuel efficiency strategy. Wheel covers are made of a variety of materials including aluminum, polycarbonate, and even cloth.
The primary design challenge has been making it possible to easily remove the wheel covers so that the wheels are accessible, while maintaining strong attachment to the vehicle over the road.
“We continue to update our fleet with more fuel efficient post-2014 U.S. Environmental Protection Agency emission compliant engines, install aerodynamic devices on our tractors, and equip our trailers with trailer blades, which all lead to meaningful improvement in fuel efficiency.” — Knight Transportation
“Appearance and detail of our equipment means a lot to our drivers. Drive wheel fairings don’t just save us money, but our drivers like them too.” — Brad Pinchuk, Hirschbach
“Sleeper tractor aerodynamics have been finely tuned by all OEMs. Eliminating various features can add 10% to a fleet’s fuel expense,” — Chief engineer at a major truck builder.
The Confidence Matrix has been issued to help fleets make decisions about tractor aerodynamic devices.