Pneumatic-thermal hybrid engine

The engine (M') has a combustion chamber connected to a pressurized gas storage reservoir (8). The reservoir and/or the chamber is supplied with pressurized gas by a gas compressor (15) that is driven by a rankine cycle expander (12) thermically coupled with an exhaust line (9) of the engine. The chamber is defined by a cylinder head (1) and a cylinder (2) accommodating a piston. The pressurized gas is directed from the chamber toward the reservoir during deceleration phase and from the reservoir toward the chamber by controlling a compressed air charging and discharging valve (6). An independent claim is also included for a method for managing combustive gas supply of a pneumatic-thermal hybrid engine.