TRAVERSE CITY, MI – A hydraulic-hybrid system for light trucks that’s said to boost fuel economy in city driving up to 60% is revealed in conjunction with the Center for Automotive Research’s Management Briefing Seminars.

The system, installed in a ’09 Ford Ranger compact pickup on display here, includes the powertrain, energy-storage system and ancillary hydraulic pumps and motors.

NRG Dynamix, based in Deerfield, MI, has had the system under development since 2004, says President James A. O’Brien II. It’s designed for Class 3-6 commercial vehicles but eventually could cover the gamut from small cars to Class 8 trucks, he says.

A standard Ranger powered by a 2.3L 4-cyl. engine gets 14 mpg (16.8 L/100 km) in city driving, O’Brien says. Using the NRG system, fuel economy climbs to “the mid 20s,” while in highway driving the specially equipped Ranger matches Ford’s fuel-economy specs, he adds.

Spartan Motors of Charlotte, MI, has installed an NRG hydraulic-hybrid system in a ’11 Ford F-350 pickup for testing, and an unnamed Detroit auto maker also has shown serious interest in the development, he says.

Auto makers in Japan, China, South Korea and India, plus federal U.S. agencies, have expressed interest, as well, O’Brien adds. NRG has seven patents on the system with eight pending, he says.
NRG claims its approach reduces cost one-third compared with electric hybrids and adds only 300 lbs. (136 kg) to vehicle weight vs. 1,000 lbs. (454 kg) for electrics.

“It’s also safer, because there’s no (battery) chemistry involved,” he says. Instead, energy from the generator and regenerative braking is stored in an accumulator.

NRG also claims its system is slightly more than half the cost of competing electric-hybrid technology for commercial vehicles.

An electrical engineer and self-taught hydraulics expert, O’Brien predicts a breakthrough for his invention by 2015 in the Class 3-6 range and eventually as a replacement for conventional hydraulic transmissions.

The system is designed to be installed easily on existing automatic-transmission lines, he notes.

Privately owned NRG has invested $14 million so far in developing the hydraulic hybrid, O’Brien says.