Diesel-electric hybrids may not be readily available yet, but interest is growing in the United States. Two announcements this week featured the vehicles, which are powered by diesel and electric engines.
At the Work Truck Show in Atlanta on Wednesday, March 1, Mitsubishi Fuso showed off its medium-duty diesel-electric hybrid cabover, destined for Japanese streets later this year. Meanwhile, the Eaton Corporation announced it will provide the hybrid power systems for 50 UPS step-van vehicles made by International Truck and Engine Corp. and Freightliner Custom Chassis. The vehicles will be placed into service in Dallas in June.
The two hybrid powerplants are similar in concept. The new Fuso system, called the Canter Eco Hybrid, combines a small, clean-burning diesel engine, an ultra-slim electric motor/generator and advanced lithium-ion batteries in a drivetrain that also includes a high-efficiency automated mechanical transmission. A Mitsubishi Fuso spokesman says that in tests, the truck has achieved as much as a 30 percent increase in fuel efficiency over similarly equipped trucks in similar urban pickup and delivery applications in Japan, the market in which the truck will debut.
The component combination is new, but the base components — a 123 hp turbocharged diesel, a 47 hp brushless permanent-magnet synchronous electric motor/generator and the Mitsubishi Fuso Inomat II automated mechanical transmission — all have been used in Mitsubishi Fuso applications.
Likewise, the UPS trucks will feature proven components in a new arrangement. The Freightliner Custom Chassis truck will use a Mercedes-Benz MBE 904 4-cylinder diesel engine, and the International Truck and Engine vehicle will employ an International VT-275 6-cylinder diesel. Those systems will combine with an Eaton automated transmission, an integrated motor/generator and advanced batteries. Eaton says the trucks can achieve a 35 percent increase in fuel efficiency.
Both systems use electrical or mechanical energy to power the trucks depending on the operating speed of the truck, and both recover kinetic energy during braking, similar to automotive systems already on American highways.
“Hybrid power is ready for broader commercialization,” says Jim Sweetnam, Eaton senior vice president and president of Eaton’s Truck Group.
Mitsubishi Fuso said it is still gauging interest in the U.S. market.