I have obtained data of the efficiencies of a few models of electric vehicles. We would like to compare them, but we have noted that the different motor power ratings may have an effect on the efficiency, as the lower rated motors had higher km/kwh efficiencies. For example, the 5 kW, 5kW, 3 kW, and 1.5 kW models would have efficiencies of 4 km/kWh, 5.7 km/kWh, 9 km/kWh, and 13 km/kWh respectively.
Would it be possible to normalize the values to remove the factor of having different motor powers, such that the efficiencies are adjusted to where all the motors seemingly have the same strength? And what method would be applicable? I first thought of linearly scaling the efficiency of the smaller motors to the large one using their power rating ratio.
There is also the question of whether normalizing the data is necessary, or if the comparison of the efficiencies with different power ratings is already fair.
Thank you very much!