advance angle u03b8 after correction has a pattern as shown in fig7 f as shown in fig7 g the output torque te of the engine abruptly increases when the accelerator pedal is depressed and then decreases slightly to form nearly the same phase and the same pattern as those of the ignition advance angle u03b8 as shown in fig7 b therefore winding of the engine speed in acceleration is decreased accordingly the derivative da of acceleration i e the longitudinal oscillation of the vehicle decreases in amplitude and rapidly converges that is to say in the example of fig7 d the derivative of acceleration converges after oscillation of approximately two periods and hence in approximately 0 5 sec fig8 a to 8e are time charts showing various data obtained when the value of k is defined to be a middle value say 4 in this case winding of the engine speed n nearly disappears fig8 a and oscillation of the acceleration a and the derivative da of acceleration further decreases fig8 b and 8c the longitudinal oscillation of the vehicle converges in approximately one period i e approximately 0 25 sec fig9 a to 9d are time charts of various data obtained when the value of k is defined to be the maximum value say 8 in this case winding of the engine speed n disappears and oscillation of the acceleration a and the derivative da of acceleration is not seen fig9 a and 9b the operation in acceleration has heretofore been described in deceleration as well the correction ignition advance angle u03b8 1 is similarly defined on the basis of the value of k and the derivative da of acceleration and the stationary ignition advance angle is corrected.