1. The problem statement, all variables and given/known data I have set myself the problem of modeling a KER's technology applied to road cars. I am looking to establish the kinetic energy of a vehicle corresponding to a specific drive cycle for instance the NEDC or similar. I have distance speed and time data for the drive cycle and also general data about the vehicle such as mass rolling radius gear ratios etc. Obviously the kinetic energy into the cycle is 0.5*mv^2 + energy required to overcome rolling resistance and aerodrag. The energy I can extract from the system is 0.5*mv^2 - rolling resistance - drag. Obviously there is drive train efficiencies in both cases. My question relates to the 0.5*mv^2 rotating parts of the car will have a rotational kinetic energy 0.5*IW^2 If i was to count the wheels in both the 0.5*mv^2 and the 0.5*IW^2 would I be counting them twice or in fact would i just be accounting for the I guess lateral and rotational energies. The wheels are really my only concern because this is energy that is harvestable other rotating components will be disengaged from the driveling during energy recovery. just 0.5*mv^2 is probably sufficiently accurate for my purposes but if I can make it more accurate I would like too. Cheers for any help.