This paper proposes a methodology of analysis based on a mathematical algorithm for determining the energy efficiency of the Series Hybrid Electric Vehicle - HEV. This system has the main part using four electric motors coupled directly to the wheels. A simulation of a HEV propulsion system was performed to compare the efficiency of this system with the electric car and a conventional car. To establish the basic conditions of the theoretical prototype was evaluated initially sizing of batteries and capacitors commercially available that meet the technical requirements for this type of vehicle. The results of the experimental analysis of conventional vehicle were obtained by Zegarra Fernando Sanchez in his master s thesis [14], and will be used in this project. This experimental analysis was obtained by developing a test bench, comprising a chassis dynamometer, an autopilot and a fuel flow meter. Later comparisons with experimental data obtained by the simulation data showed a maximum efficiency of the HEV regenerative model of 47.66 per cent. Thus one can also show that the minimum cost for an urban route was RS. 11.6 / 100 km and a highway cycle the minimum cost was RS. 16.6 / 100 km. In the analysis of energy efficiency, regeneration efficiency and cost per route, were also made calculations of the cost of adapting this system to a conventional vehicle, aiming at an analysis of future viability.