PURPOSE: To secure safety and reliability of a tire and turning travelling at the time when air pressure is lowered by controlling an engine so that an output characteristic against an operating amount of an accelerator pedal becomes a specified basic characteristic and at the time when tire air pressure is lowered, it becomes a correction characteristic on the output restraining side.

CONSTITUTION: A tire air pressure judging device, in accordance with each of output signals from each of front, rear, left and right wheel speed sensors 51-54 in an automobile and an initializing switch 55 on an instrument panel and others, drives and controls a warning lamp 56 of the inner panel and others by a control unit 50. That is, at the time of detecting lowering of tire air pressure, warning is output. In this case, an operating amount of an accelerator pedal 17 is detected by an acceleration sensor 19. Additionally by an engine control device 20, an engine 5 is controlled so that an output characteristic against the operating amount of the accelerator pedal 17 becomes a specified basic characteristic. In the meantime, at the time when the tire air pressure is lowered, the engine 5 is controlled so that it becomes a correction characteristic on the output restraining side rather than the basic characteristic.