TORONTO, Ont. – Eaton’s Hydraulic Launch Assist (HLA) hybrid system was on display in Canada for the first time recently at the City of Toronto’s Green Fleet Expo. A Peterbilt Model 320 refuse truck decked out in Waste Management livery was on display at the show, where it attracted much attention from municipal fleet managers in attendance. The HLA hybrid system will go into production later this year on Peterbilt trucks.

Eaton designed the HLA system which, like its hybrid-electric system, generates power under braking. However it does not require an electric motor or battery pack. Regenerative braking occurs when the driver takes their foot off the gas.

“As it’s slowing down, the pump is engaged,” Vincent Duray, chief engineer, hydraulic hybrids with Eaton told Truck News. “It’s pressurizing the accumulator and through that increasing pressure you’re actually slowing the vehicle down. When you step back on the gas, that energy is re-applied back to the drivetrain.”

The regenerative braking process slows the truck to 2 mph. The driver brings the truck to a complete stop by applying the brake pedal. As a result, brake life is extended at least 250%, Duray said. The system also improves fuel mileage by 20-30% by assisting the diesel engine during launches, and it allows trash collectors to pick up more bins per day thanks to the instantaneous power transfer at starts.

Even without government incentives, Duray said a payback period of three to five years is expected in refuse applications.

The hybrid components are mounted on the frame rail underneath the body. They collectively weigh about 1,200 lbs, but Eaton is still working on reducing some of that weight. It’s a parallel system, meaning the truck can still be operated if the HLA system is off line.

Eaton’s HLA hybrid system is ideal for stop-and-go applications such as refuse. Its hybrid-electric system is better suited for applications where the electric motor can be used to power auxiliary devices such as a man lift.

“We are going to let the application decide which is best for that particular service and application so we don’t have to force one solution that may not be the best,” explained Duray. “Our viewpoint is, let the market decide (which technology is best).”

Eaton’s HLA system will be available in two modes: performance and economy. Performance mode is intended for applications where the vehicle can take advantage of the extra power during frequent starts. In performance mode, vehicle acceleration is improved by 26%. In economy mode, engine torque is limited so even greater fuel savings are attained, Eaton officials claim. This would be ideal for smaller trucks or those working in tight spaces with fewer starts and stops.

Inside the cab, a small display shows the driver the state of charge as well as fault codes and service lights. Maintenance is simple, Duray said, since servicing requirements have been synched up with general preventive maintenance schedules. The HLA system is designed to last 10 years, which is the typical life-cycle of a refuse truck.

Peterbilt announced availability of its low cab-forward Model 320 with the HLA system at this year’s Mid-America Trucking Show.