TheDenver Regional Transportation District (RTD) celebrated the addition of four buses powered by General Motors’ diesel-electric hybrid propulsion system to its mass transit fleet.
Metropolitan Denver is the 37 th community to invest in transit buses powered by General Motors’ hybrid technology, which offers greater fuel economy and significantly reduced emissions compared with conventional diesel buses.
Attending a media event at Denver Union Station celebrating the addition of the GM hybrid-powered buses to Denver RTD’s fleet were U.S. Sen. Ken Salazar along with representatives from Denver RTD, Gillig Corp. and General Motors.
“We are pleased to officially launch our new hybrid buses today. Placing them into regular daily service will give us a real indication of performance and passenger acceptance,” said Clarence W. Marsella, general manager, Denver RTD.
Buses powered by GM’s advanced hybrid propulsion technology deliver significantly better fuel economy than traditional buses and produce up to 60 percent fewer oxides of nitrogen emissions and 90 percent fewer particulate, hydrocarbon and carbon monoxide emissions. Other benefits of the buses include reduced maintenance costs resulting from extended brake, engine oil and transmission oil life; providing 50 percent faster acceleration compared with conventional diesel buses, and operational sound levels approaching that of passenger cars.
“GM’s two-mode hybrid technology offers significantly improved fuel economy, along with reduced noise and emissions – qualities that are particularly important and beneficial in cities like Denver,” said Beth Lowery, GM vice president of environment and energy. “We applaud Denver for its efforts to protect the environment today, and to help preserve it for generations to come.”
Since 2004, more than 445 GM hybrid-powered buses have been delivered to 37 communities in the U.S. and Canada. The estimated annual combined fuel savings for the 446 GM hybrid-powered buses is 650,000 gallons.
“The General Motors hybrid diesel-electric drive system for buses uses the most efficient parallel hybrid architecture available in the world today,” said Tom Stephens, group vice president of GM Powertrain. “If the U.S. had only 1,000 GM hybrid powered buses operating in major cities, the cumulative savings would be more than 1.5 million gallons of fuel annually.”
By the end of the year, another 189 GM hybrid-powered buses are expected to be delivered.
The clean hybrid technology is manufactured by GM Allison Transmission, maker of transmissions and hybrid propulsion systems for commercial trucks, buses, off-highway equipment and military vehicles, headquartered in Indianapolis. Gillig Corp. of Hayward, Calif., manufactured the buses.
The two-mode hybrid technology in these buses has served as the starting point for GM’s co-development with DaimlerChrysler and BMW Group of a two-mode hybrid system for light-duty vehicles that GM will launch next year in the Chevrolet Tahoe and GMC Yukon fullsize SUVs, followed by the Cadillac Escalade in 2008.
The Atlas 20 Hybrid, released in Japan, achieves a 35% improvement in fuel economy in M15 mode and improvements of 10% to 20% in normal city driving. The vehicle’s CO2 emissions drop by 25% in M15 mode. M15 mode is the standard used in Japan for measuring the fuel efficiency of urban heavy-duty vehicles.
The Hybrid employs a power-take-off (PTO) type parallel-drive hybrid system in which the motor/generator is connected to a different drive shaft from the engine for reliable operation. Even if a failure occurs in the hybrid system, the vehicle can still be driven using the diesel engine.