Advanced hybrid technologies developed jointly by Peterbilt Motors Co. and Eaton Corp. have been integrated into an aerodynamically styled heavy-duty vehicle designed for superior fuel efficiency and greater environmental stewardship.
Wal-Mart Stores, which operates the nation’s second-largest private fleet, is supporting development of new hybrid technologies by helping to validate the concept and refine the final design.
Wal-Mart recently announced its “Sustainability 360” program that will aggressively promote environmental stewardship among customers, suppliers and associates through a number of global innovation projects. Peterbilt and Eaton previously have partnered to develop hybrid electric Class 6-7 vehicle platforms and Class 8 hybrid hydraulic vehicles. With a successful test and evaluation program, the heavy-duty hybrid electric power system will be available in 2009.
“We are pleased to partner with Peterbilt to produce a heavy-duty hybrid truck that we believe delivers a strong value proposition,” says Jim Sweetnam, Eaton senior vice president and truck group president. “During the past five years, we’ve clearly demonstrated our leadership in the hybrid marketplace with the success of our patented hybrid power system in the medium-duty marketplace. We’re excited that Wal-Mart’s fleet is now seeing the value of our hybrid technology.”
“Peterbilt and Paccar are leaders in developing solutions that help customers improve fuel economy through superior aerodynamic designs and advanced technologies,” says Bill Jackson, Peterbilt general manager and Paccar vice president. “We continue to design products, improve processes and develop technologies that are environmentally responsible. As we refine our heavy-duty hybrid platform for future production, we are fortunate to have Eaton and Wal-Mart as partners to help develop the best possible vehicle system for both customers and the environment.”
“Wal-Mart is careful to consider the civic and environmental impact its operations have in the communities it serves around the world,” says Tim Yatsko, Wal-Mart senior vice president of transportation. “We are continually looking for new, innovative ways to improve the fuel economy and reduce the emissions of our fleet. We currently operate the Peterbilt Model 386, and we anticipate that the hybrid version will help us move toward our goal to increase our fleet efficiency by 25 percent over the next few years.”
During third-party testing, the Eaton Hybrid Power System has routinely achieved a 5-7 percent fuel savings versus comparable, nonhybrid models. It may result in a savings of one gallon of fuel per hour when idling. At the current average diesel price of almost $2.50 per gallon, those savings equate to about $9,000 to $10,000 a truck per year in operation.
The heavy-duty hybrid electric power system features 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 Eaton’s Fuller UltraShift transmission. The system captures energy generated by the diesel engine and recovers energy normally lost during braking, and stores the energy in batteries. That electric torque then is sent through the motor/generator and blended with engine torque to improve vehicle performance, operate the engine in a more fuel-efficient range for a given speed and/or operate only with electric power in certain situations.
In this heavy-duty application of Eaton’s hybrid power technology, fuel efficiency and emissions reductions are best achieved both while the truck is rolling or standing still. The system’s batteries power the heating, air conditioning and vehicle electrical systems while the engine is off. When the idle reduction mode is active, engine operation is limited to battery charging, an automatically controlled process that takes about five minutes per hour to fully charge the system. In the proposed system design, a proprietary feature minimizes engine vibration during startup and shutdown during the recharge periods, allowing the driver to rest without interruption.