While the development of medium-duty hybrid trucks continues on a number of fronts, the size of vehicle fleets used by North America’s package delivery operations puts that market segment high on the list of opportunities for development that make the most economic sense.

Desiring to foster more of this activity, and to take the development work from the lab to the road, a partnership led by CALSTART’s Hybrid Truck Users Forum (HTUF) has selected Hybra-Drive Systems LLC to build three Class 6 hydraulic hybrid delivery trucks for testing by UPS, FedEx Ground and 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.”

The government-corporate partnership led by CALSTART that selected Hybra-Drive Systems is funding the project with money from the U.S. Department of Energy. The U.S. EPA unveiled the first hydraulic hybrid diesel urban delivery vehicle in June 2006. Since then, several vehicle manufacturers have been working on the technology.

Hybra-Drive, based in Deerfield, Mich., was selected for the HTUF project from among roughly four dozen companies that responded to a Request for Proposals issued last September. Working in conjunction with Gates Corp., Detroit Custom Chassis (a subsidiary of Spectra LMP, LLC) and Morgan Olson LLC, Hybra-Drive proposed a series hydraulic hybrid vehicle (HHV) based on a Ford chassis for the validation project.

Hybra-Drive will build and deliver the three hydraulic hybrids over the next nine to 12 months. UPS, FedEx Ground and Purolator then will conduct a six to nine month evaluation of the vehicles. Hybra-Drive hopes the evaluations will demonstrate up to a 60 percent cut in fuel use along with an accompanying reduction in emissions. 

Hybra-Drive’s approach is unique in that it has developed a hydraulic fluid transmission to go along with the hydraulic pumps and storage tanks that are used to store energy. In its design, a gasoline, alternative fuel or diesel engine can be used to operate a hydraulic pump that pressurizes a stored energy hydraulic system to propel the vehicle. The Hybra-Drive hydraulic-hybrid powertrain system is also designed to not add extra curb weight compared to the standard vehicle. 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.

The Hybrid Truck Users Forum, one of several national programs operated by CALSTART, is a leader in the development of alternative fuel vehicles. HTUF’s Parcel Delivery Truck Working Group is building on the success of the HTUF Utility Truck Working Group and its initial deployment of 24 International Truck/Eaton hybrid electric bucket trucks. That project led to the announcement by International of limited production of Class 6 hybrid electric trucks, and the development of similar vehicles from Peterbilt, Kenworth, and Freightliner.

For UPS, FedEx Ground and Purolator, all of which have experience with both hydraulic and electric hybrid parcel delivery vehicles, participation in this project enables them to explore other technology options and better understand the relative merits and benefits of different technical approaches.

In the not too distant future, fleets in a variety of industry segments will be able to explore and realize the value of all these efforts.