A new solution introduced by this site describes an alternative engine configuration with toroidal oscillating pistons, named Hybrid Opposite Piston Engine – HOPE, that attempts to correct certain deficiencies of the thermodynamic cycle as employed in conventional engines. Why this engine can be considered “hybrid”? The answer is: because can achieve by itself the braking energy recovery in city drive and the exhaust gas recovery in highway drive. HOPE can work as four-stroke or as two-stroke engine.

Same HOPE concept can be used for hybrid electric vehicles or for the electric vehicles with extended autonomy as range extender, having a number of advantages and offering for the first time the possibility to achieve a new type of means of transport: the Electric Vehicle with Portable Range Extender.


 A new Total Heat Recovery Engine – TOHRE
is proposed. Instead of “toroidal” cylinders
this uses “cylindrical’ cylinder and linear motion
for the pistons. Comparing with actual concurrence
represented by Ecomotors solution, the TOHRE
benefits are:

1. Exhaust heat and cooling heat recovery;
2. Integrated supercharger instead of external/
additional/expensive electric supercharger;
3. More compact and less weight reported to the
same power;
4. Can be built also as a four stroke engine;
5. Improved mechanical efficiency;
6. Compensation of all rotating inertial forces;
7. Compensation of all 1st order oscillating forces
(torque compensation);
6. No exotic solutions for the motor mechanism or 
for valve mechanism;
8. Lowest fuel consumption between 95 and
145 g/kWh;
9. Less number of components and cheaper design;
10. Also fully balanced in the simpler variant and very
attractive as range extender;
11. Very easy and cheap prototyping and consequently
less risks of development.

More details at:






TOHRE example: 0.8 l; 300 kW (400 HP); 48 kg