Improvements in automotive fuel economy

Significant improvements in automotive fuel economy can be obtained by reductions in weight, aerodynamic drag (better streamlining) and rolling resistance (tire improvements), as well as by improvements in engine and powertrain efficiency. As applied to a six-passenger, 3700 lb present-day vehicle powered with a 250 CID six-cylinder engine through an automatic transmission, the improvements in EPA M/H fuel economy for 1% reductions in either weight, aerodynamic drag or rolling resistance are projected to be 0.75, 0.35 and 0.28%, respectively. This is under the constraints of constant performances and equal emissions. The extent to which large changes in these parameters can be obtained, resulting in significant improvements in fuel economy, depends not only upon solving manufacturing and technical problems related to costs but also upon government regulations and customer acceptance in the marketplace. If large reductions in these parameters could be accomplished, along with realistic improvements in engine and powertrain efficiency, significant improvements in fuel economy could be achieved.