LAS VEGAS – Autocar LLC and Parker Hannifin Corp. unveiled a working prototype of the E3 heavy-duty hybrid truck at Waste Expo in Las Vegas, reports FleetOwner, as reported by the Web site Initially intended for Class 8 refuse truck applications, the truck features a hydraulic hybrid system that uncouples the engine from the drivetrain and replaces the transmission with a hydraulic pump and hydrostatic engines. During fuel consumption tests, Autocar has recorded up to a 50-percent decrease. The E3 is also reported to reduce brake wear and operating noise. The E3 is a hydraulic hybrid that collects energy from vehicle braking and stores it as compressed hydraulic fluid in accumulators. The accumulated fluid drives hydrostatic motors, which then deliver power to the driveline. When the vehicle reaches 24 mph, or when the accumulated pressure is depleted, the truck’s 8L Cummins ISL diesel drives the vehicle’s hydraulic pumps and hydrostatic motors. At speeds above 40 mph, the hydraulic unit bypasses the pumps and becomes a direct-drive transmission with a top vehicle speed of approximately 65 mph. A small number of beta vehicles will be built this year for field and fleet testing, with a limited commercial launch anticipated in late 2007 or early 2008, the report said.