To analyze the impact of cobalt iron cores in the design of interior permanent magnet synchronous motors (IPSM) for competition electric vehicles, a spoke-type IPSM geometry is optimized considering FeSi and VaCoFe cores. This optimization is done for a range of torque/efficiency, to provide a general comparative analysis between materials considering the application of a FormulaStudent 4-motor competition car’s powertrain. A genetic optimization algorithm (NSGA-II) is applied over a hybrid analytical/finite-element model of the motor to provide sufficiently accurate electromagnetic and thermal results within a feasible time. It is shown that machines with VaCoFe core are a better alternative across both considered torque and efficiency ranges. VaCoFe can result in an estimated increase of up to 3% in efficiency for the same torque, or up to 70% torque increase for the same efficiency level. However, because of the density difference between materials, core weight is similar for the overlapping torque range. For the competition car, with a required 20Nm of nominal torque, there is an efficiency increase of 1.7% and a reduction of 11% in core volume for the motor with VaCoFe compared to FeSi.