PURPOSE: To control output within an allowable torque without giving a discomfortable feeling to a driver in spite of a small-sized transmission mechanism by alloting the torque of an engine so that a specific condition is satisfied and by opening/closing-controlling a throttle valve according to the allotment.

CONSTITUTION: The gear ratio of a driving system of an engine is detected by a means 2, and the generated upper limit torque of the engine with each detected gear ratio (speed change position) is calculated by a means 3. Further, the upper limit throttle opening degree for generating the calculated upper limit torque is calculated by a means 4, and the calculated upper limit throttle opening degree is allowed to accord with the perfect opening point of the accelerator opening degree, and calculation is performed by a means 5 so that the throttle valve opening degree corresponding to the accelerator opening degree ranging from the perfect closure point to the perfect opening point is successively increased and alloted. Further, on the basis of the accelerator opening degree detected by a means 1 and according to the calculated throttle valve opening degree quantity allotment, a means 6 calculates the throttle valve opening degree control quantity. A means 7 opening/closing-drives the throttle valve 8 according to the calculated throttle valve opening degree control quantity.