The main design criteria for the modern sustainable development of vehicle powertrains are the high energy efficiency of the conversion system, the competitive cost and the lowest possible environmental impacts. An innovative decision making methodology, using multi-objective optimization technics is currently under development. The idea is to obtain a population of possible design solutions corresponding to the most efficient energy system definition. These solutions meet technical, economic and environmental optimality. This article applies the methodology on an electric vehicle, in order to define the powertrain configuration of the vehicle, to estimate the cost of the equipment and to show the environmental impacts of the technical choices of the powertrain configurations in a life cycle perspective. A physical model of the electric vehicle is made and coupled with a cost model for the vehicle and LCA (Life Cycle Assessment) technics are used for the environmental assessment. After multi-objective optimizations with thermo-economic and environmental objectives, the solutions obtained from the Pareto frontiers curve are analyzed. Conclusions about the environomic design of the vehicle for optimal mobility service are made. The greenhouse gas emissions are calculated from a well-to-wheel perspective for different countries of use of the electric vehicle, according to their respective electricity production mixes.