This paper provides analyses, models and a new frame design for the Csiro electric drive for solar cars. The main objective is to determine whether the axial flux Csiro motor (CM) is more efficient than the radial flux Biel motor (BM). To do that, performance tests were conducted and both drives were compared. Results showed that the CM is more efficient at low torques. The same results were used to derive and validate a steady state model for the CM. The model was based on four major losses in the CM. Using the model it was possible to determine the areas where improvements were possible to boost the efficiency, to optimize the mechanical design and to calculate the losses and efficiency of the CM when subjected to certain loads.@en