Wal-Mart Stores Inc. on Feb. 2 said it will test a new type of heavy-duty commercial hybrid truck and a new type of alternatively fueled truck, developed by Bellevue, Wash.-based PACCAR.

The tests are part of the company's efforts to develop a more sustainable trucking fleet. The new trucks include five Peterbilt Model 386 heavy duty hybrid trucks with diesel-electric hybrid power systems developed by Eaton Corp., four Peterbilt Model 386 trucks, and one yard truck retrofitted to run on liquid natural gas.

Wal-Mart achieved more than a 25 percent increase in efficiency within its private fleet between 2005 and 2008, surpassing one of the company's stated sustainability goals. By reaching this goal, Wal-Mart has been able to reduce its carbon dioxide emissions and its fuel use. This goal was reached by using a combination of new technologies, better delivery routes and by loading its trailers more efficiently.

The company continues working toward its goal of doubling its fleet efficiency by 2015, from its 2005 baseline. Part of this pilot program is to determine if alternatively fueled trucks can help move Wal-Mart toward that goal in addition to reducing environmental impacts.

Wal-Mart has actively engaged several suppliers to develop and test these new technologies. This includes Arvin Meritor, Eaton, Peterbilt and International as well as smaller companies such as Environmental Development Group, which will retrofit the trucks to run on waste cooking grease. Wal-Mart will test these new technologies throughout 2009.