@ajay123
I think one of your stumbling blocks is you confusion of ratings too, take a 3ph 3kw motor for instance, this is not 3kw of electrical power it draws from the mains, it relates to the available mechanical power at the shaft, this is why it used to be written in horse power and sometimes still is.
A motor gives a mechanical output measured in Kw or HP
A Gen' gives an electrical output measured in Kw or KVA (Where Kw is used then a PF of 0.8 is assumed as this is an unknown quantity as the manufacturer cannot determine the users load).
So when you start looking at your designs you have to decipher and/or convert values to get a true overview, also you have to realise that stored potential energy will be quickly lost when loaded up unless you maintain the full mechanical energy input (in the case of a generator) to get the rated electrical output.
To generate this mechanical movement you can use a variety of methods but unless its free energy source like a waterwheel using a river or wind etc then any other method like compressed air for example will always require more energy to compress the air than the can be extracted from the system to run a generator.
The maths can be very complicated when working power ratio's out in several formats but this is how you determine whether any system efficient, if you try to apply said calculations to any of your theories it will always show you what you are trying to do cannot ever work, you are in a sense trying to visualise an idea without the bother of all the complicated calculations - this is your biggest downfall but even that aside we use a seperate easier to understand response by expressing the issues of losses, inertial energy (stored power) etc.
The only way to do this without calculations is to do visual analogies which I kindly did many posts ago, this will apply to all such overunity systems where as in your recent idea you just need to change the moped for a large pressurised gas tank blowing the car on the flat which is conceivable but the minute you add load to the car IE an incline then the potential energy quickly disappears and the remaining compressed air cannot overcome the added load of the incline - in this case the load is trying to pressurise the gas which in turns pushes the car.... you end up with a graph where the line fall almost vertical of the paper as everything simply stalls.
