On-Road Evaluation of Devices to Reduce Heavy Truck Aerodynamic Drag

Several practical devices to reduce aerodynamic drag on a typical class 8 line-haul tractor-trailer application were evaluated last year by this author and Fongloon (Peter) Pan in SAE 2007-01-1781 [Reference 1]. Those evaluations were conducted via reduced scale wind tunnel testing and focused on three areas within the tractor-trailer system: tractor-trailer gap, trailer sides and trailer aft body.

This paper builds on our previous work, and presents the results of full scale, on-road fuel economy tests of a select sub-set of those devices. The on-road fuel economy testing was accomplished in accordance with SAE Type II (J1321) test procedure [Reference 2].

An 11.5% improvement in highway fuel economy was demonstrated for a select combination of devices.