An ECT_ECU performs a program including: a step of determining whether the gears are being changed or the gears are not being changed; a step of setting the virtual gear to the current gear, if the gears are not being changed; a step of setting the virtual gear to the gear before the gears are changed, if the gears are being changed but the inertia phase has not been started; a step of setting the virtual gear to the gear after the gears are changed, if the gears are being changed and the inertia phase has been started; a step of calculating the gear-change progress .alpha.; a step of calculating the virtual gear ratio based on the virtual gear and the gear-change progress .alpha.; and a step of calculating the target engine torque using the virtual gear ratio.