DETROIT – Based on experience with a hydraulic-hybrid (HH) military truck, Dana Corp. says the cost of the technology, when applied to a garbage truck, for example, may be offset within as little as one year of service.

Echoing the outlook of other advocates of hydraulic-hybrid technology applied to frequent stop/start vehicles, the Toledo, OH, supplier says the net combination of high-efficiency hydraulics and large fuel and maintenance (notably brake repair) savings is driving the technology ahead.

Pump motor is placed between engine and rear axle on this hybrid military demonstration vehicle on display at Dana’s SAE pavilion.

Edward Greif, Dana’s group vice president-Engine and Fluid Management Group, says a program to demonstrate a hydraulic-hybrid refuse truck in California is being driven by a team composed of the California South Coast Air Quality Management District, National Automotive Center, Federal Signal Corp. (truck body), Mack Trucks Inc. (chassis) and Dana (HH system).

First demonstration is expected next year.

Greif says the outlook for quick investment payback, reduced fuel use and lower emissions is favorable to a degree that once the system is proven in use, "we believe that existing refuse trucks will be retrofitted with HH (hydraulic-hybrid systems)."

He points to the layout of a system displayed on a military truck at the Society of Automotive Engineers World Congress, which places the pump/motor in-line between the engine and rear drive axle. Space is available for this and the high-pressure hydraulic accumulators under existing truck designs.

Asked what he believes are the next targets for hydraulic-hybrid systems, Greif says urban transit buses and delivery vehicles.

He says these applications also will benefit from lower cost and higher efficiency compared with electric-hybrid systems.

Greif says the military truck hybrid control system can be set to provide maximum fuel economy for most non-combat uses and then alternatively for maximum performance in combat.

He says this also can be applied to civilian truck applications seeking either best fuel economy or best performance.

He acknowledges some of the forthcoming passenger-car electric-hybrid systems are being marketed more for their performance than fuel economy.

The military application stems from a cooperative research and development agreement between Dana and the National Automotive Center targeted at Army medium tactical vehicles.

The technology, termed “intelligent hydraulic drive” for the military, originated with Permo-Drive Technologies. Specialty equipment maker Stewart & Stevenson of Sealy, TX, will make the hardware for military vehicles. (See related story: EPA to Unveil Hydraulic Hybrid at SAE)