An engine controller controls an injection quantity or intake airflow supplied to a cylinder of an engine. Constant associated with e running resistance of the vehicle are reconfigured according to vehicle specifications when a change is made to the vehicle specifications. A target acceleration is determined from the accelerator operation amount. An acceleration resistance is determined using the target acceleration and a constant based on the vehicle weight. At least an air resistance and a rolling resistance are added to the acceleration resistance to determine a running resistance for accelerating or decelerating the vehicle at the target acceleration. A driving wheel torque is determined using the running resistance and a constant based on the effective tire radius. An engine output shaft torque equivalent to a driver-requested torque is determined using the driving wheel torque and a constant based on the final gear ratio.