Using the overall efficiency obtained with today’s automotive power plants on the U.S. Metro Route as a baseline for comparison purposes, this paper reviews the major efficiency opportunities available in the next decade for a wide variety of automotive engine candidates. The impact of a variety of alternate fuels on candidate engine thermal efficiency is also presented. A family of continuously variable transmissions, having different levels of efficiency, are then used to project the overall efficiency of these engine candidates and fuels on the U.S. Metro Route in the 1990+ time frame. The direction of engine design, material and control trends during this time interval are also discussed.
