Yosemite Celebrates Delivery of New GM Hybrid Buses

Published June 1, 2005

National Park Service Deputy Director Don Murphy and Yosemite National Park on April 25 celebrated the delivery of 18 new General Motors hybrid buses that promise to reduce noise and emissions in the park while simultaneously providing better acceleration and general performance than existing buses.

Economy and Performance

“In addition to improved fuel economy and a reduction of certain emissions by up to 90 percent, the GM hybrid system delivers superior torque; derived from the dual electric motors used to launch the bus, with 50 percent better acceleration than conventional diesel buses,” reported Minnesota Public Radio. “All of this is achieved with operating sound levels comparable to that of passenger cars. The hybrid powertrain also helps to extend brake, engine oil, and transmission oil life.

“The National Park Service’s concern for increasing noise and emissions levels in the Yosemite Valley were the main factors behind the decision to replace its existing fleet of conventional diesel buses with hybrid-powered buses,” added the radio report. “Yosemite joins the growing ranks of cities, counties, and transit authorities that have invested in GM’s advanced hybrid propulsion system for buses, which offers greater fuel economy and dramatically lower emissions over conventional diesel buses. GM hybrid-equipped buses are operating in 22 cities across the country.”

Park Service Praises GM

“These GM hybrid-powered buses exemplify the National Park Service’s efforts to simultaneously provide unparalleled visitor service while taking a leadership role in greening the environment through federal fleet and transportation efficiency,” said Murphy.

“This bus uses the most efficient parallel hybrid architecture available in the world today, and has served as a starting point for GM’s co-development of a two-mode full hybrid system for applications in trucks, cars, and sport utility vehicles with a variety of drive configurations, such as front-, rear-, and all-wheel drive,” said Tom Stephens, group vice president of GM Powertrain, in a company news release. “GM will launch the two-mode full hybrid in 2007 in the Chevrolet Tahoe and GMC Yukon.”

Analysts Impressed by Performance

“They are welcome replacements for the rattly, stinky, diesel-only shuttles that hauled tourists throughout the Yosemite Valley since 1986,” noted the May 13 issue of AutoWeek magazine. “The ‘hybridized’ [transmission] is so efficient and robust that it will be introduced on the Tahoe and Yukon in November 2007, and forms the basis for a joint venture with DaimlerChrysler for many hybrid vehicles to come.”

Added the April 25 Detroit News Auto Insider, “The two-mode hybrid version that will eventually go into consumer vehicles is being jointly developed by GM and DaimlerChrysler AG. The companies say it will improve fuel economy by at least 25 percent in light trucks.”

James M. Taylor ([email protected]) is managing editor of Environment & Climate News.