This is an excerpt from EERE Network News, a weekly electronic newsletter.
General Motors and DaimlerChrysler to Team Up on Hybrid Vehicles
DaimlerChrysler AG and General Motors Corporation (GM) announced on December 13th that they will work together to develop a hybrid propulsion system for use in GM, Chrysler Group and Mercedes Car Group vehicles. Although both companies have been working independently on their own hybrid propulsion systems, they have signed a non-binding "memorandum of understanding" for the joint hybrid project and intend to enter into a definitive agreement in early 2005. See the GM press release.
The companies will be working on a patent-protected hybrid system that incorporates two electric motors into an electrically variable transmission, creating a system that uses much smaller motors than today's hybrid vehicles. The system appears to be modeled on a drive for buses and other transit vehicles developed by Allison Transmission and used by GM in its hybrid electric buses, since both the system under development and the Allison system are described as "two-mode" hybrid systems. The Allison system uses the electric power of the motors to accelerate from a stop, then uses the engine to assist at higher speeds. At high speeds, the engine will power the vehicle without help from the motors. Both the motors and the engine can independently drive the wheels. See the description of Allison's hybrid drive on the Allison Transmission Web site.