Run flat tyres for C5 X7?

[osx]

Are these type of tyres suitable for a C5 X7 Exclusive? Been told that they are much heavier compared to normal tyres but also more stiff so not good for the ride.

[vborovic]

http://en.wikipedia.org/wiki/Run-flat_tire" onclick="window.open(this.href);return false;

So ... it depends, from the tyre model/manufacturer ... why, do you expect to still be driving at high speeds after the puncture? ...

[osx]

One thing is for sure, that I wont be driving at any speed with a normal punctured tyre.

[Hell Razor5543]

As I understand it, run flat tyres work by having much stiffer sidewalls, so they can support the weight of the car even when there is insufficient air pressure to take the weight. The downside is that the ride comfort takes a beating. Tyres are only part of the ride comfort equation (the springs and shock absorbers (or, in the case of Citroens) the hydro pneumatic system) making up the rest, and if one component is out of sync the equation 'fails'.

[vborovic]

Wait another year when they start building these for the road use ... http://www.michelintweel.com/" onclick="window.open(this.href);return false; ... ... but in case you don't have tyre pressure sensors, and your run flat tyre deflates/punctures ... how will you feel it? Surely there must be some difference to the drive?

[osx]

It is not a matter of feeling but more a matter of safety. There is no question that run flat tyres are safer. The question is if they are "bad" for hydractive suspensions.

[bobins]

As I understood it, you're only supposed to put runflat tyres on cars with TPS as there's the chance you wouldn't know you've got a deflating tyre if you didn't have TPS - especially on Hydractive suspesnion.

[vborovic]

That's my view exactly ... just curious about that, that's all ... about being bad for a hydractive suspension, I guess in the normal lifespan of a hydractive car, the car drives over rough surface anyways, the tyre stiffness shouldn't be any extra burden on the driving experience ...

[osx]

As I understood it, you're only supposed to put runflat tyres on cars with TPS as there's the chance you wouldn't know you've got a deflating tyre if you didn't have TPS - especially on Hydractive suspesnion.

Don't think that is correct as you would want to know if you had a slow puncture with any tyre.

[qprdude]

Have you seen the price of them?

[bobins]

Don't think that is correct as you would want to know if you had a slow puncture with any tyre.

I appreciate that if you trawl the internet you'll probably find a counter argument, but National Tyres clearly state......

"Fitting Run Flat to an older vehicle ('retro fitting')

If you are considering changing to run flat tyres on a vehicle that was previously fitted with 'normal' tyres, then there are several points to consider:

Tyre Pressure Monitoring System
Run flats must only be installed on a car which has TPMS/tyre pressure monitoring system. TPMS alerts the driver to a puncture so they are aware that they have a limited time to replace their tyre, and so they drive within the limits of their deflated tyre (see our section on tyre-pressure for more detail)

Vehicle Suspension
You should also note that you may need some changes made to your vehicle’s suspension. Because of their stiffer construction, run flat tyres contribute to a vehicle’s suspension when fitted as original equipment."

http://www.national.co.uk/information/r ... tyres.aspx" onclick="window.open(this.href);return false;

[osx]

I wouldn't go with what National Tyres recommend.

Interestingly I found the following which throws another spin

.... from 2012 tyres and Tyre Pressure Monitoring Systems (TPMS) will form part of the MOT. Having non-run-flat tyres fitted to a car that comes OEM with run-flats will be a fail...

Now need to check if the C5 came with TPMS.

[vborovic]

Exclusives should have the TPM system per default, mine doesn't ... at least in our market area ...

[osx]

Mine doesn't have the CHECK button at the right of the steering wheel so probably doesn't come with TPM

Driver request detection
You can check the tyre pressures
at any given moment. To do so,
press on button A (CHECK) ; the
information will be displayed on the
instrument panel screen.

[qprdude]

Mine does