"Run Flat Tyres"

[R1Geezer]

I hear this expression all the time on motoring programs etc but I'm often confused by the meaning. Now I know that it means that tyres when punctured will still be usable, ie fitted to VIP cars etc etc. Now I've also heard it used to refer to bottom of the range BMW's etc where it surely does not mean the same thing so hence the confusion, I think the latter may be referring to the bit of the tyre that touches the road being flat rather than concave, can any enlightened soul clear this up, thanks.

[ChuckFickens]

they are not puncture proof, run flats just allow you to carry on driving after you get a puncture.

There are two run flat systems. one works by having a very stiff side wall of the tyre so if it does get a puncture the strength of the side wall will still hold the tyre in shape and allow you to continue driving, the other works by having a thick support band around the center of the wheel rim, if the tyre gets a puncture the car drops onto this support band which supports the car so you can carry on driving.

[chas2008]

you can fit run flats to amost anything if the size is available, they are just a silly price..

[chas2008]

i said almost anything, when genuine alloys are ordered there is no mention of which type of tyre is fitted, i know owners who have replaced the runflats when knackered by standard tyres (cost issue ) this was done by a reputable tyre dealer the down side is no spare but as with many modern cars they just invested in a tyre weld type kit

[stoofur]

I assume that the run flat tyres would need to be replaced shortly after being punctured. I also though that BMW used this system so that they don't have to supply a spare wheel?

[dalebillster]

Im pretty sure that run flat tyres allow you to drive upto a maximum of 50mph & for a range of upto 100 miles. Im not sure on some models of car but on the BMW run flat tyres they are 10x thicker than average tyres...