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Idle Reduction

The Fleet Test and Evaluation team is working with industry partners to study idle reduction technologies that keep truck cabs comfortable without having to run the engine.

In 2002, the Fleet Test and Evaluation team and the U.S. Department of Energy initiated a study of diesel-truck engine idle reduction technologies. The evaluation was broken into three projects composed of teams that included a fleet, a truck manufacturer, and an equipment manufacturer. The projects were led by Schneider National, Caterpillar, and Espar.

Schneider National

Led by Schneider National and completed in 2005, this project evaluated climate control systems installed in 120 Freightliner Class 8 heavy-duty trucks. Of them, 100 trucks were equipped with Webasto's Air Top 2000 cab heater and 20 featured the company's the Cab Cooler. The trucks were operated by Schneider National, a shipping company whose trucks averaged about 480 idling hours per year.


Diagram of Caterpillar's MorElectric technology showing the integration of the auxiliary power unit; the heating, cooling, and ventilation system; and the generator.

The Fleet Test and Evaluation team studied Caterpillar's MorElectric auxiliary power unit, which can keep a truck cab comfortable without idling the engine (courtesy of Caterpillar).

Led by Caterpillar, this project demonstrated the company's MorElectric technology in five new International Class 8 heavy-duty trucks operated by Cox Transfer, a truckload and flatbed carrier whose trucks averaged 1,840 hours of idling per year. Field testing ended in late 2006.


Led by Espar, this project evaluated the company's heating and cooling systems in 20 International Class 8 heavy-duty trucks operated by Wal-Mart Transportation, a company that provides trucking services for Wal-Mart retail stores and distribution centers. Data collection ended in late 2006.

The results of these studies are featured in the following documents, which are available as Adobe Acrobat PDFs.