GM Hybrid-Powered Buses Get Seattle Transit Contract

May 17, 2007
Contract may increase fleet to more than 700 GM-hybrid powered buses

King County, Washington was awarded a landmark contract today for the purchase of up to 500 articulated buses, most of which will be powered by General Motors' 2-mode hybrid system.

The five-year contract, which could be worth as much as $400 million, is between King County and bus-manufacturer New Flyer Industries. General Motors supplies New Flyer with the hybrid system for the buses.

King County has been operating a fleet of 214 GM hybrid-powered buses since 2004 and with the addition of this contract, King County could have a total of 714 buses, making it the largest fleet of hybrid-articulated buses in history.

In the U.S., GM's strategy is to save as many gallons of fuel as possible by applying hybrid technology first to larger vehicles such as mass transit buses. Currently, 720 buses with GM's 2-mode hybrid system have been delivered to 56 cities across the U.S. and Canada, saving an estimated 1 million gallons of fuel annually. The potential addition of up to 500 buses in King County will bring the total, in North America, to more than 1,200 GM hybrid-powered, saving an estimated 1.75 million gallons of fuel annually.

Transit buses with GM's 2-mode hybrid system deliver significantly better fuel economy than traditional transit buses, cut certain emissions up to 90 percent and have operating sound levels approaching that of passenger cars. Other benefits of GM's 2-mode hybrid system for transit buses include reduced maintenance costs resulting from extended brake, engine oil and transmission oil life, superior torque, and improved acceleration.

In fact, the National Renewable Energy Laboratory (NREL) conducted a one-year comparative study between conventional diesel buses and GM hybrid-powered buses operating on a typical King County drive cycle.

The NREL report showed that the GM-hybrid powered buses achieved 30 percent higher fuel economy on average when compared to the conventional diesel buses and total operating costs were lowered by 15 percent.

The 2-mode hybrid technology in these buses has served as the starting point for GM's co-development with DaimlerChrysler and BMW Group of the 2-mode hybrid system for passenger vehicles, that GM will launch later this year in the Chevrolet Tahoe and GMC Yukon fullsize SUVs, followed in 2008 by the Cadillac Escalade fullsize SUV, Saturn Vue Green Line compact SUV and the Chevrolet Silverado and GMC Sierra fullsize pickups.

"The Chevrolet Tahoe and GMC Yukon are the world's first and only fullsize hybrid SUVs, offering up to eight-passenger seating and an estimated 25 percent improvement in overall fuel economy when combined with our Active Fuel Management cylinder deactivation technology," said Beth Lowery, GM Vice President, Environment, Energy and Safety Policy.

The 2-mode hybrid diesel-electric drive system for transit buses is manufactured by GM Allison Transmission, maker of transmissions and hybrid propulsion systems for commercial trucks, buses, and off-highway equipment and military vehicles, headquartered in Indianapolis.

During King County drive cycle testing, the NREL results showed that the GM-hybrid powered buses lowered fuel consumption by 23 percent; nitrogen oxides (NOx) by 18 percent; carbon monoxide (CO) by 60 percent; and total hydrocarbon (THC) by 56 percent when compared to conventional diesel buses.

This NREL study of King County's hybrid buses is an endorsement of GM's 2-mode hybrid propulsion system and one element of King County's decision to purchase up to 500 additional buses. The report was published in December 2006, and can be viewed at

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About the Author

Brad Kenney | Chief Marketing Officer

Brad Kenney is the former Technology Editor of IndustryWeek and now serves as director of the mobile/social platforms practice at R/GA, a global marketing/advertising firm in New York City.

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