Estimating Effect of Vehicle Characteristics on Fuel Consumption

Abstract

The effect of vehicle characteristics on fuel consumption is calculated using a basic energy-related model of instantaneous fuel consumption and on-road second-by-second speed, acceleration, and grade data. By integrating the instantaneous model over observed on-road speed profiles, aggregate models have been derived with vehicle parameters explicit at all model levels. Using this approach, interpretation of the parameters of the well-known average travel speed model is possible. The constant term in this model is related to the fuel to provide tractive force to the vehicle and the coefficient of the reciprocal of average speed can be interpreted as the idle fuel consumption rate. The effects of engine capacity and mass on the parameters of the average travel speed model are discussed. This approach is then compared with the estimated effect of engine capacity on fuel consumption derived using the average travel speed model and official fuel consumption tests.