HIGH EFFICIENCY
HYBRID CYCLE
(HEHC)

  • Compression: For maximum efficiency, air is compressed to a high compression ratio, fuel is injected and compression ignited (CI-HEHC). The X Mini utilizes a spark-ignition (SI-HEHC) version of the cycle with a lower compression ratio standard for gasoline engines.

  • A dwell near top-dead-center forces combustion to occur at nearly constant-volume conditions.

  • Combustion products are over-expanded using a larger expansion volume than compression volume, as in the Atkinson Cycle.

  • Cycle-skipping power modulation allows high efficiencies at low power settings while simultaneously cooling the engine’s walls internally and providing partial heat recovery.

  • Water may be injected to internally cool the engine. Some of this cooling energy is recuperated, as the water turns to steam, increasing the chamber pressure.