Any power you get from doing that will come ultimately from the gasoline in the engine. If you think you could get something "free" in this way, you are mistaken.
I don't think it would be that free, just reclaiming some of the energy used.
Oh okay. But, would the slowing down and speeding up of a car be able to produce the change of force?
But you would NOT be "reclaiming some of the energy used", you would be requiring the use of MORE gas and wasting some of it in various inefficiencies to get an end result that you can already get from the car's alternator. Your statement makes me think that you DO somehow believe that there would be something free involved.
Ah ha ! You DO think it's free energy. Certainly, you could generate energy but this would be at the expense of the kinetic energy of the car, as provided by the gas engine. If you wanted to keep the car running at the same speed as it would if you were not harvesting energy the way you suggest, you would have to supply more energy via the engine. Can you not see that were it otherwise this would be free energy? Free energy leads to perpetual motion machines. They don't work.
Adding such a device would reduce the aerodynamic efficiency of the car/increase drag.
Correct ... it would be a net loss of energy, as I have said repeatedly.
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