Engine of a spark ignition type

摘要

An internal combustion engine of a spark ignition type is so arranged as to set an air-fuel ratio of a mixed fuel to become substantially stoichiometric in the range of from A/F=13 to A/F=16 at the time of running in a high load region and to recirculate exhaust gases into the intake system. For the internal combustion engine of a natural intake type, the compression ratio is preferably set to 11 or larger; for the internal combustion engine of a supercharging type, the compression ratio is preferably set to 9 or larger. The rate at which the exhaust gases are recirculated is preferably set to be constant or to become larger as the load of the engine becomes larger.