That means the tire's structure is able to securely withstand the weight of the vehicle and its passengers in case of air pressure loss. When air pressure leaves the tire, due to damage, such as punctures, it can still be driven for 50 miles up to 50 mph. As a result, a limited, temporary performance is guaranteed, as the vehicle will not be stranded with a flat tire. Run flat tires should not be mounted on the same vehicle as regular tires since they have heavier constructions.