The present paper introduces a new integrated method for an energy performance analysis of the hybrid electric vehicles. This method takes into consideration the acceleration and deceleration factors that influence the energy efficiency. The research is based on Matlab modeling and Hardware in the Loop approach. The added value is given by the accuracy of the model that is part of the simulation together with the presented performance analysis methods. A set of 10 case studies are proposed and the efficiency of the method is demonstrated through a series of simulation results. The motivation of the research is given by the fact that the actual fleet of hybrid electric vehicles faces many challenges regarding the driving range which makes the energy efficient operation critical. The advantage of this method is that the systems performance can be validated to a large extent from an early stage. The results can contribute to the practical need of developing hybrid and electric vehicles with a higher energy efficiency and with lower costs.