CONTROL METHOD AND CONTROL DEVICE FOR A SPARK-IGNITED INTERNAL COMBUSTION ENGINE

An internal combustion engine (1) is a spark-ignition internal combustion engine comprising a turbocharger (2) and an exhaust gas recirculation device, and operation according to a stoichiometric air-fuel ratio is performed by performing exhaust gas recirculation even in a high-load range including a maximum-output operation point. When the maximum output operation point is required (step 1), intake air information such as atmospheric pressure and outside air temperature (step 2) is used as a basis to calculate intake air density (ρ) (step 3), which is compared with a predetermined density threshold (ρ#) (step 4). When the intake density (ρ) is equal to or less than the density threshold (ρ#) at a high-altitude location or the like, an exhaust gas recirculation rate is set to 0 (step 6). As a result, the maximum output can be higher than when exhaust gas recirculation is performed.