Statistical Analysis of Six-and Eight-Cylinder Passenger Car Engine Quality

The methodology developed in an earlier SAE paper prepared by two of the authors for estimating the relative fuel efficiency of four-cylinder spark ignition engines from EPA vehicle certification data was extended to six- and eight-cylinder engines for 1978, 1979, and 1980 model years. The empirical model expresses variations in vehicle weight specific fuel consumption resulting from variations in the vehicle parameters. The model coefficients were estimated by regression analysis and used to normalize vehicle weight specific fuel consumption by minimizing differences among vehicles. Engine quality indicators were derived from ranking individual engine types.