Run Flat Tires . . . . ?

Question

If you have “run flat tires,” how would you know that you had an actual flat? How much do they cost, for an average size sedan?

Answer 1

Run flat tires have stiff sidewalls that are able to support the weight of the vehicle with no air pressure. They drive like a seriously low tire. While you can drive them at 55 mph or less, they will heat up and damage themselves if you take them up on their mileage. A simple nail hole plug will result in a requiring a new tire if you run them for any period of time at higher speeds. If the tire does run flat, drive slow and avoid any potholes at all costs. The sidewalls probably won't do much for absorbing such large shocks and will probably damage the rims.

Also, they are about twice as expensive as simular sports tires, and they have significantly less lifetime mileage.

On the other hand, I've driven very slowly with two blown regular tires and the rims were not damaged. Kind of an SOL situation there.

Answer 2

ALL vehicles fitted with Run Flat tires are equipped with a tire pressure monitoring system of some sort which will warn the driver if one or more tires is under-inflated.

There are 1,740 different tire sizes last time I checked, there is no longer any such thing as "an average sedan".  Prices will vary widly from one application to another depending on year/make/model of vehicle and tire manufacturer.