of these vehicles may go well beyond the precompetitive R&D boundaries that define USCAR's cooperative work. Because each manufacturer views the market somewhat differently, each is expected to develop a different type of concept vehicle. They will also have different approaches to mass reduction and will use different power train configurations. All three manufacturers have programs to develop hybrid-electric power trains, and many different configurations and degrees of hybridization are possible. Also, in the next few years, some test-bed cars that incorporate one or another advanced concept will continue to be built and tested, in addition to vehicles that meet all of the PNGV concept vehicle criteria.
In spite of this diversity, many areas of precompetitive research have still not been explored. All of the most promising technologies listed above still require major development before they will be serious candidates for use in mass-produced passenger cars and trucks. Reducing the cost of these technologies is the most common concern.
Some of the technologies being explored (e.g., fuel-cell power plant, advanced batteries, ultracapacitors, and flywheels) are very promising but are unlikely to be ready for application in full-concept vehicles before 2000. These technologies are expected to be developed under the PNGV cooperative program and incorporated in post-2000 concept vehicles.
All three USCAR partners have DOE-supported HEV programs that started at different times and have somewhat different goals. The vehicles being constructed under these contracts should not be confused with the concept vehicles being built for the PNGV program. They will not necessarily meet the criteria for the PNGV concept vehicles. For example, they were conceived as vehicles that would deliver only twice the baseline fuel economy. Nevertheless, these programs will speed the development of components specifically suited for HEV applications and increase the expertise in systems management issues associated with this complex power train.
Recommendation. The relationship between the criteria for technology selection and the critical requirements of Goal 3 should be made more explicit to facilitate the proper distribution of resources for an ongoing, well structured research and development program.