Partially premixed combustion (PPC), also known as PPCI (partially-premixed compression ignition) or GDCI (gasoline direct-injection compression-ignition) [1][2][3][4] is a modern combustion process intended to be used in internal combustion engines of automobiles and other motorized vehicles in the future. Its high specific power, high fuel efficiency and low exhaust pollution have made it a promising technology. A PPC engine injects and premixes a charge during compression stroke.