Runflats, Why do they give lower performance ?

[Minipnut]

Just wondering as my new car has funflats
CHeers
Pnut

[S33BBY]

The short answer is because they're extremely heavy in comparison with a normal tyre, and they extremely rigid too. Have a search and you'll find loads about runflats!

[Rakey]

Quote: Originally Posted by S33BBY (original)

The short answer is because they're extremely heavy in comparison with a normal tyre, and they extremely rigid too. Have a search and you'll find loads about runflats!

correct, this along with the density and compound of rubber means that they are slow to warm up, give less grip due to this, and carry the extra weight that Seb mentioned

[hyperbluejames]

So all in all, they're great if you have a blow out, but more dangerous in every other road condition?

[S33BBY]

I don't know about dangerous, but certainly not very good!

[Mon the fish]

Tyres and suspension work the same -

Stiffer = changes direction faster
Softer = more compliant and more grip

Weight is most evil when its unsprung (i.e. tyres, wheels, brakes, track rods etc.), the car reacts slower when these parts are heavier.

This explains the harsher ride and less grip (runflats being stiff and heavy), but it doesn't explain why I found mine to wear out quicker than normal tyres did. Maybe they're made softer to counteract the lower grip levels?

[Haggi]

its also down to the side wall being so strong that causes them to wear faster but compared to some budget non rfs that ive driven on other cars the run flast on the mini aint to bad esp the newer generation ones

[midge]

I know tyres all have different weights, but how much heavier are runflats compaired to nonrunflats, for say a 17' tyre?