Due to the increase of the electric vehicle market, the mileage of the electric vehicle with full battery gets importance. The ambient temperature or the abuse driving conditions directly affects the mileage of the electric vehicle. To increase the mileage, the analysis of the thermal management system of the electric vehicle should be studied well. Besides the battery, one of the most important components of an electric vehicle is the synchronous motor. Thus, this study focused on the cooling methodology of permanent magnet synchronous motor which is limited in the literature. The cooling methodology of the synchronous motor directly affects battery performance. To analyze the thermal management system of an electric vehicle, analyzing the synchronous motor cooling water circulation methodology is taken into account and numerical simulations are validated by experimental results with 0.2% error. The effect of the mass flow rate of the motor coolant on the pressure drop is also analyzed.