Since 1968, vehicle weight increases and emissions controls have reduced fuel economy substantially. Additional losses in economy and acceleration will be experienced through 1976. Recommendations are made to lessen the impact of the predicted losses.Factors influencing fuel economy and acceleration are examined for an intermediate car. Changes in engine efficiency and displacement, compression ratio, torque converter, transmission, axle ratio, aerodynamic drag, tires, accessories, vehicle weight, and emissions controls are examined. When practical, the effects of 10% changes are analyzed. Comparisons are also made with a subcompact and a luxury vehicle.