hcci

GM demonstrated the combustion process, known formally as Homogeneous Charge Compression Ignition or HCCI, for the first time in two driveable concept vehicles, a 2007 Saturn Aura and Opel Vectra. When combined with the enabling advanced technologies, direct injection, electric cam phasing, variable valve lift and cylinder pressure sensing, HCCI provides up to 15 percent fuel savings, while meeting future emissions standards.