Hybra-Drive plans hydraulic hybrid

June 1, 2008
A government-corporate partnership led by CALSTART has selected a Michigan firm to build three identical hydraulic hybrid delivery trucks for real-world

A government-corporate partnership led by CALSTART has selected a Michigan firm to build three identical hydraulic hybrid delivery trucks for real-world testing by UPS, FedEx Ground, and Purolator.

The partnership, CALSTART's Hybrid Truck Users Forum (HTUF), selected Hybra-Drive Systems LLC to build three large Class 6 trucks for road testing that incorporate the firm's approach to the promising hydraulic hybrid technology.

Under the new agreement, which is being financed by the 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 then 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 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.