Allison Expands Global Market Leadership in Parallel Hybrid Drives for Buses

INDIANAPOLIS, Sept. 23, 2008 - Allison Transmission, Inc., the world's leading supplier of commercial duty fully automatic transmissions and hybrid propulsion systems, continues to be a dominant force in the hybrid bus market both in North America and Europe. As of August, more than 1,100 GM-Allison two-mode parallel hybrid-equipped buses have been delivered to 94 cities worldwide. They've driven a total of 134,071,230 kilometers, saved an estimated 16,761,237 liters of fuel and eliminated 43,842 metric tons of carbon dioxide from the atmosphere. And more GM-Allison hybrid-equipped buses are rolling off the assembly line daily.

"Since the hybrid propulsion technology was introduced, these systems have enjoyed enormous success in the bus marketplace, proving that we developed the right technology at the right time," says William E. Klenk, Director of Allison Electric Drive and Off-Highway Operations. "While our initial success came in North America, European cities are starting to embrace this technology as environmental concerns and rising fuel prices worldwide require public transit authorities to seek alternative systems."

Phileas articulated trams in Istanbul, Turkey and Douai, France are operating with GM-Allison two-mode parallel hybrid technology, as are buses in Germany and Switzerland. In fact, second-generation hybrid buses are now on the roads in Bremen, Munich and Hanover, Germany two years after the first Solaris 18 GM-Allison made its European debut. A smaller diesel engine mated to an optimized GM-Allison two-mode hybrid system guarantees even lower fuel consumption and better efficiency.

"We found an experienced and reliable partner for the development of hybrid buses for the European market. With the second generation of the Solaris hybrid bus, we experienced fuel savings of up to 24 percent fuel. That's a quarter of the way toward independence from diesel, and we are delighted to follow this route in cooperation with Allison," says Krzysztof Olszewski, CEO, Solaris Bus & Coach S.A.

Hybrid technology is the preferred bus technology in the North American bus industry with more than 30 percent of the buses being built today with hybrid propulsion systems. U.S. cities such as Seattle, Philadelphia, Washington D.C., Albuquerque, Houston, St. Paul and Honolulu continue to order GM-Allison hybrids, but at increasingly larger quantities.

Says Jim Boon, Vehicle Maintenance Section Manager with King County Metro Transit Division in Seattle, Washington, "In June we added 22 more hybrid articulated buses so we now have 257 units in our fleet. The new buses all blended in with the existing hybrids without fanfare. In July we logged just over 910,000 miles on the hybrid fleet. Performance remains outstanding with continued good fuel economy and excellent fleet availability."

Also notably, at Yosemite National Park, the entire fleet of buses has been replaced with quiet GM-Allison two-mode hybrid-equipped buses to operate in this pristine natural setting.

The GM-Allison hybrid system uses two-mode parallel hybrid technology that combines drive from a conventional diesel engine and an electric drive motor. Depending on conditions and vehicle speed, the system's controller selects the appropriate power source or a blend of both.

The heart of the system is the EV Drive(TM) unit, an infinitely variable transmission that allows the hybrid system to run quieter, cleaner and more efficiently. Depending on duty cycle, the EP System(TM) has proven in Europe to improve fuel economy by up to 24 percent and dramatically reduce diesel engine emissions, including carbon dioxide and particulate matter.

Acceleration is also markedly smoother when compared to conventional diesel-powered vehicles, and with intelligent processing, the GM-Allison hybrid system delivers the best performance and fuel economy across a broad range of driving conditions. With regenerative braking allowing the vehicle to create additional energy normally lost through braking, the system is particularly well suited to demanding stop-start urban bus routes.

Allison Transmission manufactures the EV Drive(TM) unit, and supplies the Energy Storage System, Hybrid ECU and Power Electronics Processor DPIM. The ability to furnish vehicle builders with the entire system, rather than forcing customers to source components individually, provides a major integration advantage over the competition.

Transit agencies acknowledge that the GM-Allison two-mode hybrid system is a commercially accepted hybrid system, including its energy storage system. Since commercial production began in 2003, there has not been a single end-of-life battery failure with the GM-Allison hybrid system. In 2007, more than 400 GM-Allison hybrid-powered buses were produced, with 360 units delivered to 36 cities. These are the highest annual totals since deliveries began.

The two-mode hybrid technology in these GM-Allison systems has served as the starting point for General Motors' co-development with Chrysler, Mercedes and the BMW Group of the two-mode hybrid system for passenger vehicles.