Visitors to Booth 3441 at the American Public Transportation Association (APTA) Expo will get a first-hand look at Allison's advanced parallel hybrid technology for the transit industry, the E^PSystem^TM. In addition, they'll learn about something perhaps even more exciting: proven commercial applications for these products. Parallel hybrid technologies developed by the Allison Transmission Division of General Motors (GM) are delivering lower emissions and improved fuel economy to a range of transit bus applications, including 40-foot standard and low-floor buses and 60-foot articulated buses and suburban coaches. An early design generation of Allison's hybrid electric technology, the E^SSystem^TM series hybrid system, currently powers demonstrator buses for the Orange County Transportation Authority (OCTA) in Orange County, California and Tri-Met Transit system in Portland, Oregon. Low emissions / high performance The E^PSystem^TM brings a range of benefits to transit applications, including much lower hydrocarbon and carbon monoxide emissions. Particulate emissions (tiny pieces of soot and dust) are reduced by up to 90 percent compared to conventional diesel buses when installed with a diesel particulate filter; NOX emissions (nitrogen oxide) are reduced by up to 50 percent. Note: These emission results have been demonstrated on the Central Business District (CBD-14) urban transit bus duty cycle. The system also enables up to 60 percent better fuel economy than a conventional diesel system in urban transit bus applications. Buses equipped with the E^PSystem^TM exhibit up to 50 percent better acceleration compared to buses equipped with a conventional diesel powertrain. The E^PSystem^TM has the cost advantage of being easy-to-integrate into various vehicle platforms. The E^PSystem^TM design is scalable to a broad range of commercial applications. "Allison's E^PSystem^TM can significantly enhance the performance of transit, suburban coaches and articulated buses operating in a variety of environments," said Fred Cartwright, program director, Allison Electric Drives. How hybrid works Here's how hybrid technology works: Hybrid systems use two sources of power to move a vehicle - engine and battery. In the parallel hybrid system, the engine-generator combination works in parallel with the battery, furnishing electrical power to keep the battery charged. The engine is coupled to a drive unit that delivers a continuously variable ratio of power to the wheels. This allows an engine in a hybrid system to run more efficiently, quietly and cleanly. For example, when the bus accelerates from a stop, the batteries supply ample power for a seamless and quiet acceleration. This eliminates the excessive diesel cloud that an accelerating bus typically emits. A parallel hybrid bus uses the diesel engine's mechanical power to maintain speed after the vehicle is underway. In this mode the engine also charges the energy storage system (battery), making it unnecessary to ever plug the vehicle in for charging. Performance data on Allison-powered buses now in operation in Orange County, CA demonstrate that 40 percent of the energy needed to accelerate the bus comes from the energy recovered and stored during the stop. Through its development process Allison determined that customary lead-acid batteries were a significant barrier to commercialization of hybrid technology. Batteries for heavy-duty hybrid electric vehicles need to give customers cost effective service life, better packaging size and be much lighter than modern lead-acid batteries. Today, Allison is offering a light-weight NiMH-based energy storage system. Allison projects the life of this system to be six years compared to less than two years for lead-acid batteries. The Allison NiMH energy storage system is one-third the weight and one-half the size a lead-acid battery based energy storage system. In 1999, Allison successfully completed a demonstration hybrid bus program for the New York City Transit (NYCT) Authority. In 2000, the company began its hybrid electric "Preview" program. This "first generation hybrid" program, the first step of which was undertaken with New Flyer of America, is bringing hybrid electric buses to transit systems across North America. California's Orange County Transit Authority (OCTA) was the first transit property to place Allison's series hybrid electric equipment installed New Flyer buses into revenue service in 2000. Tri-Met transit in Portland, Oregon added two of the Allison series hybrid powered New Flyer buses to their fleet in April 2002, Philadelphia-based South Eastern Pennsylvania Transportation Authority (SEPTA) will take delivery of their first New Flyer bus equipped with the E^PSystem^TM, Allison's parallel hybrid propulsion system, in September 2002. Allison is supplying "preview" E^PSystem^TM equipment to New Flyer Industries, Gillig Corporation and Motor Coach Industries for installation in additional "Preview Program" hybrid buses and coaches for delivery to select transit operators nationwide in 2002. Allison plans to start regular production of the E^PSystem^TM system late 2003. Allison Transmission leads the world in the design, manufacture and sales of medium- and heavy-duty automatic transmissions. Founded in 1915, the General Motors division has produced and sold nearly four million transmissions.