Patent attributes
A throttle position corresponding to a R—R torque representing a torque in which a reserve torque is added to a required torque at MBT is computed. The throttle position is offset by an amount of a reserve torque in a torque increasing direction. An ignition retard amount for obtaining the required torque is computed based on a ration between the required torque and the R—R torque to cancel an increment in torque due to the offset of the throttle position. Because the offset amount of the ignition timing in the retard direction can be computed without an estimated torque which is determined based on the intake air flow rate including the leak air, it is restricted that the ignition retard amount becomes too large even if the large amount of leak air is generated at the throttle valve.