The Energy Management Strategy (EMS) to reduce comprehensive cost of EVs can be approached based on the efficiency improvement using a model, considering various parameters in co-ordination. The main parameters considered are vehicle mass with various resistances such as rolling resistance and average resistance. The energy desired from primary source of battery and emergency source of supercapacitor is consider in the model. Further the model considers energy conversion via converter, bus to motor. The mechanical output of motor is managed by power train/drive train, Hence, overall efficiency improvements is achieved by reducing losses at various stages, such as switching losses of converter, transmission loss of bus, frictional and magnetic loss of motor and energy loss of drive train. The internal considerations for the above loss reduction are discussed in detail along with supercapacitor support in case of emergency and also reverse generation by means of regenerative braking.