ArvinMeritor's prototype heavy-duty truck equipped with the first Meritor diesel-electric drivetrain was presented to Wal-Mart in Februry. Wal-Mart, which operates nearly 7200 heavy-duty trucks in North America, will test and evaluate the vehicle in regular service at one of its distribution centers throughout 2009. The Meritor hybrid drivetrain was developed specifically for linehaul, over-the-road trucks in collaboration with Navistar and Cummins. It is comprised of a proprietary motor/generator unit, high-capacity lithium-ion batteries, and overall power-management system. Also outfitted on the Wal-Mart tractor are a Meritor tandem drive axle and MeritorWABCO antilock braking system with integrated stability control and driver assistance systems.