A camber angle applying device is controlled to adjust the camber angle of wheels to a predetermined value. Therefore, the characteristics (or a high gripping property) of a high gripping force and the characteristic (or a low rolling resistance) of a small rolling resistance can be separately used as the performance of the wheels. By utilizing the high gripping property of the wheels, therefore, a vehicle is enabled to reduce its energy consumption, while retaining its running characteristics (such as a turning performance, an accelerating performance or a braking performance), by utilizing the rolling resistance of the wheels. Moreover, the camber angle applying device is controlled to reduce the rolling resistance of the wheels, so that the energy loss to occur in the wheels during running can be reduced to further reduce the energy consumption of the vehicle.