How it s possible to run a real cars not toy cars with 12 volts what will be the horsepower for those cars?

Real cars do run at 12 volts (voltages should be a little over 13 volts with engine running because of alternator output). The horsepower is determined by the engine type. Gasoline is used as a form of chemical energy when it is ignited inside the engine's combustion chambers, which creates the power responsible for moving the car.