The results show that among the analyzed parameters, the increase of transmission efficiency of the powertrain improves the vehicle energy economy most. The decreases of gross vehicle mass, aerodynamic drag coefficient and roll resistance coefficient are the next. 在所分析的车辆参数中,动力系统效率的提高对车辆能量经济性的改善最为有效,其次是车的总质量、空气阻力系数和滚动阻力系数减小的影响。