This paper presents a comparison of electromechanical system used in a vehicle with three different on-board voltage levels. The electromechanical system is composed of interior permanent brushless synchronous motor - IPM and electronic control unit - ECU. Three voltage levels are analyzed in order to increase systempsilas efficiency and decrease systempsilas weight. Additionally, the important factors for an electromechanical system like: torque vs speed characteristics, power density, sizing and robustness are compared.