Improving the performance of electric vehicle traction system can improve their autonomy without increasing the amount of batteries. In the case of electric motor, a compromise is necessary between power density and efficiency: more one charges the motor, more its efficiency tends to deteriorate because the increase in current density on the one hand, the magnetic flux density on the other hand, have a negative effect on Joule losses and iron losses. One way to offset this trade-off is to use materials with different characteristics. FeCo sheets, very efficient, are disqualified by their price; SMC iron powders are potentially interesting at high frequency but their lack of medium frequency permeability confines them to specific applications.