micro
If the vehicle currently can go 200 miles on one fillup of air, how much would that cost in gas?
...ya use gas or electricity or coal (some form of energy) to run the pump that fills the tank with air and it would take more energy to get enough pressure in the tank to do the job than it would to just use the original energy source as fuel. Got to do with the laws of thermodynamics which I don't completely understand, but I do know that any attempt to convert one form of energy into another results in a loss of energy.
This compressed air thingy is kinda like trying to propel a tank with farts. (I have been able to move one a couple of feet myself, but that is about all!!)
BTW: In this compressed air thingy was half empty, the "horsepower" would be reduced to half as well.