DALLAS, Tex.-The big green Pete doing laps at the Texas Motor Speedway this week was unlike any other heavy-duty truck you’ve ever seen.

From the outside, it looked like a run-of-the-assembly line 2008 386. But in fact, it was a prototype hybrid, forerunner of technology that Paccar and Eaton have been working on and hope to have in production by the end of 2009.

This week, the two companies announced they have entered into an agreement to jointly develop proprietary hybrid technology for heavy-duty commercial vehicles in North America.

Paccar and Eaton have been jointly working
on hybrid truck technology for years.

“Paccar and Eaton developed the technology utilized in previously announced Kenworth, Peterbilt and DAF medium-duty hybrid trucks that will be launched next year. This heavy-duty hybrid technology agreement is a natural extension to the existing partnership,” said Tom Plimpton, Paccar president.

Eaton’s heavy-duty hybrid electric power system will be built using an automated manual transmission with a parallel-type “direct” hybrid system, incorporating an electric motor/generator located between the output of an automated clutch and the input to a Fuller UltraShift transmission.

One feature of this system, the key to all diesel/electric hybrid powertrains, will be its ability to recover energy normally lost during braking and store the energy in batteries. When electric torque is blended with engine torque, this stored energy is used to improve vehicle performance, operate the engine in a more fuel-efficient range for a given speed or operate with electric power only.

The truck takes off under electric power and the diesel kicks in during acceleration and then cuts out again automatically during deceleration.

Also, the prototype on display at Dallas employs Paccar’s recently introduced hotel-load power systems for driver comfort: Kenworth CleanPower and Peterbilt Comfort Class. “These factory installed climate control systems (designed for KW and Peterbilts) provide heating and cooling plus 110 volts of power for up to 10 hours without the need to operate the engine,” said Dan Sobic, Paccar senior vice-president.

Sobic estimated that this alone could reduce fuel economy by up to eight percent.

PACCAR engineers are still ironing out some minor wrinkles before turning the plans for mass-production of these hybrids over to the folks at the assembly line.