Peterbilt-Eaton HLA Trash Truck Is Quick Off The Line

Of all the 19 hybrid vehicles available for driving during HTUF's event in Seattle, the longest line by far was formed by people waiting to get their hands on Peterbilt's 320 trash pick-up chassis outfitted with Eaton's Hydraulic Launch Assist.

It was the newest type of hybrid at the meeting and word got around that the truck was fast.

Here's why: HLA, when fully pressurized, sends 2,550 pounds-feet to the drive axles, and that tremendous torque happens right off the line. Guest drivers had to be warned to go easy on the accelerator in the initial startup, which led into an immediate left turn. They did, and no onlookers got run over (unlikely anyway, as organizers were obsessive about safety.) Torque is so strong that it snapped some pinion bolts in a differential, and engineers had to install bigger-capacity gears.

Hydraulic torque dissipates quickly, but the Cummins ISM-330 revs up soon after launch and takes over the acceleration work. Partly because of this, the engine in a heavy hybrid truck must be about the same size as for a normal truck. Engine horsepower is also needed when the truck is working on an uphill street, where little or no hydraulic pressure will be generated, and when it's at cruising speeds.

To get a good feel for the truck, I took two passes through the coned course on the parking lot of Quest Stadium, home of the NFL's Seattle Seahawks. A good football player could outsprint a normal garbage truck - not that he'd want to, I suppose - but this one would outrun him. Acceleration was almost exciting and I was pushed gently against the seat.

Soon after accelerating I stepped on the brake pedal. Each time, the hydraulic pump on the driveline was driven by the truck's kinetic energy, boosting fluid pressure in HLA's accumulator that was then used on the subsequent launch. The system's controls were set to retard whenever the driver releases the accelerator, and this slowed us while also building pressure.

Tests show that retarding cuts brake wear by 50 percent, while hydraulically assisted launching saves up to 30 percent in fuel. And exhaust emissions are cut by 40 percent. For the demo the chassis had strapped-on ballast weights and we could only scoot ahead to grab imaginary trash cans. But it will get a body with an automated sidearm when it goes to work for Waste Management. Such trucks already work fast, but this truck's quicker acceleration will speed the truck through its runs and boost productivity. Peterbilt promised a more extensive drive, and you can bet that I'll be looking forward to it.