An adaptive charge mixture control for an internal combustion engine includes four input signals supplied to an OR gate to generate a net "go rich" signal supplied to a servo motor controlling an air/fuel charge mixture control valve for an internal combustion engine. The servo is also supplied with a "go lean" fixed signal tending to lean out the air/fuel mixture. The four "go rich" signals include a first signal derived from a comparison of engine speed with a predetermined minimum (i.e., idle) level; a second signal derived from comparing throttle positions with a preset minimum throttle position; a third signal derived from comparing engine deceleration rate with a preset engine deceleration rate; and a fourth signal derived from a measurement of engine instantaneous power output.