GM gets HCCI engines on the road

摘要

GM has built two road-going prototypes with homogeneous charge compression ignition (HCCI) engines. The OEM said the technology can contribute to fuel savings of 15 per cent, compared to a conventional port injected engine. The prototype combines HCCI with direct injection (GDI), electric cam phasing, variable valve lift and cylinder pressure sensing. The fuel economy improvements seem modest - GDI alone should be 15 per cent more efficient - but this is an early prototype.