Abstract
Over the last quarter of the 1900s, the U.S. Environmental Protection Agency (EPA) has annually tabulated the fuel economy and performance characteristics of the new passenger-car fleet. Fuel economy was measured over the EPA combined urban and highway driving schedules. The performance metric was the estimated acceleration time from a standing start to 60 miles per hour (mph). In the present study, the interplay among factors influencing these characteristics is reviewed. Then, for the average new car in a given year, the manner in which fuel consumption and acceleration time are influenced by vehicle weight and engine power are examined. The departure of individual vehicles from this average trend is considered. Finally, a few of the prominent powertrain characteristics responsible for improvements in the tradeoff between fuel consumption and performance are listed.
