Ignition timing control apparatus of on-vehicle internal combustion engine

摘要

An ignition timing control apparatus of an internal combustion engine (2) mounted on a motor vehicle is provided which can prevent occurrence of the knocking. When the engine (2) is running within a specific speed range and the transmission gear ratio (GR) is high, the control device determines that the engine (2) is running within an easy-to-knock range in which the knocking is likely to occur. Accordingly an ignition timing retard control of the internal combustion engine (2) is accomplished.