Hydraulic hybrid truck tested by courier trio

WASHINGTON — A government-corporate partnership led by Calstart’s Hybrid Truck Users Forum has selected Hybra-Drive Systems LLC to build three Class 6 trucks for real-world testing by UPS, FedEx Ground and Canada’s Purolator.

"We are increasingly convinced that this technology offers a chance to — fairly quickly — improve the fuel mileage of large trucks," said Bill Van Amburg, senior vice president of Calstart. "We’ve seen several innovative approaches for this type of vehicle, and this is one that our team wants to test to help speed introduction."

Under the agreement, funded by the U.S. Department of Energy, Hybra-Drive will build and deliver three hydraulic hybrid trucks over the next nine to 12 months.

UPS, FedEx Ground and Purolator will conduct a six- to nine-month evaluation of the vehicle. Hybra-Drive hopes the evaluations will demonstrate up to a 60 percent cut in fuel use along with an accompanying reduction in emissions.

In a hydraulic hybrid truck, a high-efficiency diesel engine is combined with a unique hydraulic propulsion system, replacing the conventional drivetrain and transmission.

The vehicle uses hydraulic pumps and hydraulic storage tanks to store energy, similar to what is done with electric motors and batteries in hybrid electric vehicles. Fuel economy is increased in three ways: vehicle braking energy is recovered that normally is wasted; the engine is operated more efficiently; and the engine can be shut off when stopped or decelerating.