A new hybrid hydraulic drive system for all types of terrestrial vehicles, including vehicles running on rails, using as prime mover any of the ICE (internal combustion engine) available or turbine, battery propulsion, electric motors, fuel cells, etc. One special variable hydraulic pump connected to the prime mover acts as a “power integrator”, receiving hydraulic power from the accumulator and mechanical power from the prime mover, to supply the desired flow and pressure to the hydraulic motors during operation. A second variable pump, reloads the accumulator with the remnant power available, if any, during the whole cycle. The accumulator is quite large and it is also used as the chassis for all terrestrial vehicles. The braking energy is returned to the accumulator. The whole vehicle is controlled by electronics, and in one embodiment, using only one joystick or pedal to control speed, direction, acceleration, braking and in some cases including steering.