Researcher Robert Englar (right) and student Daniel Hegeman adjust blowing slots on an inverted model truck in GTRI's low-speed wind tunnel.

Researcher Robert Englar (right) and student Daniel Hegeman adjust blowing slots on an inverted model truck in GTRI's low-speed wind tunnel.


Aerodynamic improvements such as rounded corners and pneumatic devices could reduce drag and improve fuel economy for heavy trucks.

Aerodynamic improvements such as rounded corners and pneumatic devices could reduce drag and improve fuel economy for heavy trucks.


Recent tests using a full-size tractor-trailer show the drag-reducing improvements, which use technology originally developed to boost jet aircraft performance, could increase the fuel economy of 18-wheelers by 11 to 12%. The improvements could also enhance braking and control. Installing fairings and rounding corners could produce fuel savings of 7%. Additional improvements could come from pneumatic devices that blow compressed air from slots at the rear of the truck to smooth airflow.

The next step will be to install the aerodynamic improvements and flow-control equipment in a fleet of trucks for long-term study. The research was sponsored by the U.S. Dept. of Defense.