ArvinMeritor recently presented Wal-Mart Stores, in Bentonville, Ark., with a prototype heavy-duty truck equipped with the first Meritor diesel-electric drivetrain.
Wal-Mart will test and evaluate the vehicle in regular linehaul service at one of its distribution centers throughout 2009.

"While most hybrid systems today are best suited for start-stop applications, our hybrid drivetrain is specifically designed for linehaul, over-the-road trucks, the largest segment of the commercial vehicle population," said Carsten J. Reinhardt, president of ArvinMeritor's Commercial Vehicle Systems (CVS) business.

The dual-mode hybrid drivetrain combines both mechanical and electrical propulsion systems. Under 48 mph, vehicle propulsion is delivered entirely through an electric motor with power from lithium ion batteries. These batteries are recharged through regenerative braking and/or an engine-driven generator.

As the vehicle approaches highway speed the drivetrain phases to a diesel-powered system with the electric motor providing power only as required, allowing for total system optimization. The system has the ability for zero-emission mode over a wide range of vehicle driving conditions, allowing the truck to operate in places where emissions are restricted, like a port or urban area.

The truck is one of a number of hybrid and alternative-fueled vehicles Wal-mart is testing in its private fleet.

Additionally, the batteries provide continuous power for hotel loads during an overnight rest period, eliminating the need for engine idling or other redundant anti-idling systems. Electrification of accessories such as the air or AC compressors provides further efficiency benefits.

More info: