progress and the efficacy of the program to meet its schedules and goals, the committee addresses several broad program issues. The committee also continues to review the PNGV systems analysis, which is essential (1) for making vehicle performance and cost comparisons for alternative vehicle configurations that incorporate widely different technology subsystem and component combinations and (2) for guiding the orderly selection and development of subsystem technologies with specific performance requirements for meeting the Goal 3 vehicle objectives.

This Executive Summary highlights the committee's principal findings and recommendations. More detailed recommendations in each of the areas addressed by the committee can be found in the body of the report. The major areas addressed in this summary are: (1) progress in research in each technical area, (2) the technology selection process, (3) the economic viability of the hybrid electric vehicle (HEV), (4) emission controls for the compression ignition direct injection (CIDI) engine, (5) the initiation of a comprehensive fuels strategy, (6) systems analysis, (7) safety, (8) the cost challenge, (9) adequacy and balance of the PNGV program, and (10) government involvement in post-concept vehicles.


The PNGV Technical Roadmap details performance objectives and lays out milestones and schedules in each major technology area; the Roadmap has been updated for most of the PNGV technologies and provides a good summary of program goals. Although some technologies have now been dropped, the principal technology areas under development in the PNGV program are energy converters (CIDI engines and fuel cells), energy storage devices (batteries and flywheels), power electronics and electrical systems, and materials. In the committee's opinion, in spite of a shortfall in resources in many areas, good progress has been made in assessing the potential of each candidate system and identifying critical technologies necessary to make each system viable. In spite of this progress, however, the committee is concerned that the pace and funding of PNGV developments may not be a level for the United States to remain competitive on an international basis. In early January 1998, individual news releases from USCAR partners recognized this possibility by announcing aggressive new technology programs that involve substantial investments. A combination of PNGV and in-house company and foreign developments no doubt provided an effective stimulus for the USCAR partners to move more aggressively.

Important technical advances during the past year are listed below:

  • Internal Combustion Engines. Excellent progress has been made in the past year in all aspects of the four-stroke direct injection (4SDI) engine program, which has focused on the CIDI engine. A lightweight CIDI engine architecture study and a dimethyl ether (DME) alternative fuel design study were completed for CIDI engines. However, as is noted below, a recent stretch research objective for particulate emissions would require major changes in CIDI technology and fuels.

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