This thesis presents two vehicle models developed for a Battery Electric Vehicles dimensioning tool based on a multi-step design approach. The final goal is to identify the main parameters of the powertrain components considering the mechanical, electrical and thermal constraints that limit the performance of the system, iteratively refining the analysis based on the outcomes of a multi-step simulation process. The work started on two pre-existing vehicle models implemented in MATLAB/Simulink environment. The first of them, called Level 0, estimates the performance of the vehicle based on the e-motor maximum power, speed and torque. Level 0 makes it is possible to individuate the range of acceptable e-motor macro parameters to meet the target performance.