A system for allowing a pneumatic tire supported on a wheel rim of a vehicle to continue in operation after rupture of the tire. The system includes an air bag container which divides the interior tire volume into a radial outer chamber providing normal pressure for inflation of the tire and a radial interior chamber, within the air bag, which is inflated to a substantially higher pressure. The container is intended to rupture when the tire is deflated by a puncture or the like allowing the higher pressure air bag to escape from its container and fill the entire tire volume at a normal operating pressure.