According to GM's announcement at the Washington Auto Show on 22 January 2008, orders measuring up to 1,732 GM- Allison hybrid buses from transit agencies based in Washington DC, Philadelphia and Minneapolis / St. Paul will mark a savings of an estimated 2.4 million gallons of fuel annually. The amount of fuel saved by running this fleet of buses is enough to fill 300 tanker trucks.

The new deliveries will add up to make the current fleet of nearly 1,000 GM-Allison hybrid buses more than double in number, and turn out to be potentially the largest single hybrid bus fleet - an order of 952, acquired by the Washington Metropolitan Area Transit Authority.

More hybrid buses are likely to join the fleet - the Southeastern Pennsylvania Transportation Authority's order for 480 hybrid buses coupled with Minneapolis / St. Paul Metro Transit's plan to purchase up to 300 hybrid buses, will see more than 2,700 units of GM-Allison hybrid buses plying in 81 cities in the US, Canada and Europe. 

 "General Motors shares a common goal with transit agencies in Washington D.C., Philadelphia and Minneapolis/St. Paul to improve fuel economy and reduce vehicle emissions with proven, durable hybrid technology ," Mark LaNeve, GM, Vice President, Vehicle Sales, Service and Marketing, said during his keynote speech at the 22 January  Washington Auto Show.

"To date, the GM-Allison hybrid system has operated successfully for more than 55 million in-service miles without an end-of-life battery failure," LaNeve added. "We're now adapting that proven two-mode hybrid technology for use in our passenger vehicles, including the 2008 Chevrolet Tahoe and GMC Yukon hybrids that go on sale this month, and the upcoming Cadillac Escalade hybrid, 2009 Chevrolet Silverado hybrid and the 2009 Saturn Vue Green Line 2 Mode Hybrid."

According to company sources, by the end of 2008, GM will offer eight hybrid models, surpassing other automakers in the US, using either GM's two-mode hybrid system or the more affordable GM Hybrid system. The company intends to introduce 16 hybrid models, an average of one every three months, through 2011.

GM debuted the hybrid technology for transit buses in 2003, followed by a steadily increasing demand each year. The 1,000th GM-Allison hybrid-powered bus will be delivered to the Regional Transportation Commission of Southern Nevada, by the end of this month.

Other milestones in 2007 for the GM-Allison hybrid system include:

•  In 2007, more than 400 GM-Allison hybrid-powered buses were produced, with 360 units delivered to 36 cities - the highest annual totals since deliveries began.
• Seattle 's King County Metro Transit Authority awarded a landmark order in May for 500 buses, most of which will be powered by the GM-Allison hybrid system.
• The first international delivery was made in May to Dresden, Germany.

"Energy diversity and environmental and technological leadership is a critical element of GM's business strategy and future success," said Beth Lowery, GM Vice President, Energy, Environment and Safety Policy. "In the US, GM's strategy is to save as many gallons of fuel as possible by applying hybrid technology first to high-volume and high fuel-consuming vehicles such as mass transit buses."

The most significant benefits GM-Allison hybrid-powered buses offer, is better fuel economy than conventional diesel buses, less emission, and lowered operating sound levels approaching that of passenger cars. Other benefits include minimised maintenance costs resulting from extended brake, engine oil and transmission oil life, superior torque, and improved acceleration.

A study conducted in 2006 by the National Renewable Energy Laboratory found transit buses with GM-Allison's hybrid technology delivered up to 75 per cent better fuel economy than traditional transit buses, and reduce emissions of nitrogen oxides (NOx) up to 39 per cent, particulate matter (PM) up to 97 per cent, carbon monoxide up to 60 per cent and hydrocarbons up to 75 per cent. The report was published in December 2006. The clean hybrid technology is licensed by General Motors to Allison Transmission, which assembles and sells the hybrid transmission to bus manufacturers.

Global provider of commercial duty automatic transmissions and hybrid propulsion systems, Allison Transmission's products are used in many sectors including bus, refuse, fire, construction, distribution, military and specialty applications.