WASHINGTON, D.C. – America could save nearly 1 billion gallons of fuel annually by adopting new aerodynamic technologies on tractor-trailer trucks, according to a two-year collaborative study conducted by members of the Truck Manufacturers Association (TMA) and the U.S. Department of Energy (DOE). The two-year study was funded by the DOE FreedomCAR and Vehicle Technologies Office through the National Energy Technology Laboratory. Four TMA members — International Truck and Engine Corporation, Freightliner LLC, Mack Trucks, Inc., and Volvo Trucks North America — comprising 75 percent of the U.S. market for Class 8 trucks, teamed with the U.S. Department of Energy to study a variety of design improvements that would reduce aerodynamic drag and significantly improve fuel efficiency. Technologies that improve truck aerodynamics in several key areas were recently displayed outside the U.S. DOE headquarters, including:

  • Gap enclosure: reduces aerodynamic drag in the gap between the tractor and trailer.
  • Side skirts: improves aerodynamics and reduces airflow under the trailer in crosswinds.
  • Boat tails: tapers back of trailer to minimize “wake” airflow.
  • Side mirror design: reconfigures shape and support systems to reduce aerodynamic drag.

    The combined effect of all aerodynamic improvements on one vehicle could result in as great as 23 percent reduction in aerodynamic drag. For every 2-percent reduction in aerodynamic drag, there is a 1-percent improvement in fuel efficiency.