Originally Posted by Potty_Pants
they are designed to allow you to drive a resonable distance to get the car tire fixed. They are designed to allow you to safely navigate a busy highway and find a safe garage/tire shop to fix immediately following the puncture.
they arent designed to drive on for days or weeks .
"While Bridgestone states that all of its new 3G RFT tires are designed to operate safely with zero pressure for up to 80 kilometers (about 50 miles), the reality is that a run-flat tire is designed to get you safely off the road and out of harm's way to where the tire may be safely serviced or replaced. In truth, a virtual clock starts ticking the moment a RFT loses pressure (the frictional stress and heat literally "cook" the service life out of the rubber compounds). Consequently, high vehicle loads, high ambient temperatures, and high speeds accelerate the clock, while light loads and cold temperatures slow it (when we experience a loss of pressure with a run-flat, we immediately pull over safely in the hope that the tire may be properly repaired before it is destroyed by driving on the vehicle). Of course, run-flat tires should never be fitted to a vehicle without a tire pressure monitoring system (TPMS)."