Effects on Fuel Economy and Driveability of Varying Dynamometer Road Load and Inertia Weight

Urban and highway fuel economy CVS tests were performed on three automobiles having different size engines-4, 6 and 8 cylinders. The vehicles were tested at sixteen combinations of inertia weight settings and total road loads to simulate a wide range of weight/power ratios. Sensitivity of the vehicles to changes in total road load during the highway cycle and in inertia weight settings during the urban cycle were noted. Comments on driveability at certain ratios were recorded. Lastly, tests at selected weight/power ratios were performed using a 5-speed gearbox vehicle to study the fuel economy effect of changes in overall gear ratios.