An engine controlling apparatus includes an engine speed detection unit that detects an engine speed, and an acceleration operation amount detection unit that detects an acceleration operation amount inputted to an acceleration pedal.The apparatus includes a first calculation unit that calculates an acceleration demand torque based on the engine speed and the acceleration operation amount, a second calculation unit that calculates an external demand torque demanded from an external controlling system, and a third calculation unit that calculates a first target torque and a second target torque based on the acceleration demand torque and the external demand torque.The apparatus includes a fourth calculation unit that calculates a maximum torque which can be generated by the engine at an actual charging efficiency, and a control unit that controls an ignition timing of the engine based on the actual torque and the first target torque.