This book examines the state of development and research progress of technologies being considered for a new generation of vehicles that could achieve up to three times the fuel economy of comparable 1994 family sedans. It addresses advanced automotive technologies including engines, fuel cells, batteries, flywheels, power electronics, and lightweight materials being developed by the Partnership for a New Generation of Vehicles -- a cooperative research and development program between the U.S. government and the U.S. council for Automotive Research. The book assesses the relevance of the ongoing research to PNGV's goals and schedule, the program's adequacy and balance, and addresses several issues such as the benefits of the hybrid versus nonhybrid vehicles and the importance of the sports utility vehicle market.