For a vehicle, the knowledge of components, characteristics, performances, and behaviors are some base elements for a successful simulation. Today's tools are offering instruments able to cover a such request and new possibilities appear. Choosing the right ones, representing the entire vehicle as a system of subsystems, integrating as much as possible the parameters of different components, are also few additional elements. For internal combustion engine vehicles, the generation and the transmission of the mechanical power to the wheels imply the usage of specific mechanic parts. From a single engine, the mechanical power is controlled to offer the requested torque and speed simultaneously to the vehicle wheels, passing by clutches and gearboxes. An electric propulsion, generating high torque at zero speed, and covering large speed area, implies less components for the mechanical transmissions. One single gear, a reducer, could cover the entire speed area request of the vehicle. On the other hand, it is possible to approach the generation of the mechanical power to the wheels, by using not only one electric motor, but one for each axle, or, even more, one electric motor for each wheel of the vehicle. This paper presents the usage of numerical simulation in such situations, emphasizing opportunities for onboard energy efficiency improvement, and opening new possibilities for optimization in multiple motor solutions.