Proposed combination : - Small Electric Motor/Alternator to operate around neutral
                                               - Freewheeling Hydraulic Pump/Motor for efficient recycling of the braking energy and to allow the engine
                                                    to operate only at its maximum efficiency conditions.
                                               - The engine is always running at full load with a 30 % efficiency, or is stopped
                                                    We can expect an average Engine + Transmission efficiency > 20 %.

                                                                                   
12O mi/gal is possible in town