scope:

This International Standard describes spare unit substitutive equipment (SUSE) for passenger car tyres. This equipment is designed to allow the user to continue the journey (with or without a stop) in a reasonably safe manner. NOTE 1 Some equipment becomes effective automatically and thus avoids the necessity of stopping the vehicle immediately for inspection and corrective action. This International Standard only aims to qualify the performance of extended mobility systems. It details specifications only for extended mobility systems suitable to permit the extended mobility of the vehicle. NOTE 2 Other types of SUSE are described in Annexes A and B. This International Standard applies from the moment the extended mobility system becomes effective, and the driver has continued control of the vehicle (in speed and direction) in order to attempt to reach an appropriate place for servicing. This International Standard does not cover - the vehicle thus equipped; - the tyre while operating in inflated mode; - the characteristics of the pressure survey device and of the warning function relative to the inflated mode or to the partially deflated mode due to slow pressure losses; - the transitory phase, if any, before the equipment becomes effective; - the inspection, assessment, and the servicing of the extended mobility system, after it has been activated in flat tyre running mode. This International Standard includes - the description of the various types of SUSE; - the description and performance levels of complete extended mobility systems. NOTE 3 The performance level which the user reasonably has the right to expect, and the restrictive conditions placed upon that level, can vary to a large degree according to the equipment installed and to real operating conditions of the tyre in flat-tyre running mode.