In the paper, an algorithm for the analysis of induction motors dedicated to the electric traction of the autonomous vehicles, with emphasis on the energetic performances, is grounded. The problem is not simple, as the motors operate at voltage and frequency different from the rated values. The authors have developed an original algorithm for estimating the variable parameters, namely the resistance and the inductance related to the magnetization circuit. On this basis, the energetic analysis of the control at constant rotor frequency was performed in two aspects: the mechanical characteristics and the speed control at constant torque or constant power, respectively. Starting from the high energetic performance of the control at constant rotor frequency, the optimal control that maximizes the motor efficiency is investigated.