Electric motor and power electronic systems are essential elements for the performance and efficiency of electric vehicles (EVs) and hybrid electric vehicles. The inadequacy of the range due to battery limitations is compensated by powertrain solutions and innovative control algorithms. Future targets of electric powertrains are mostly based on weight, space, and efficiency issues. Highly efficient low-volume and lightweight propulsion systems increase the performance of EVs and also enhance their importance as an alternative to internal combustion engine vehicles. In this paper, a detailed propulsion system design study is presented by considering all of the important constraints of the electric powertrain. The design criteria and output, which are opposites of each other, are submitted in terms of their advantages and disadvantages. The tests of all constraints are conducted as a whole and discretely and then the effects of electrical machine and power electronics circuits are presented.