Run flats vs Std Tyres

[RickS1K]

My car is a beemer, which came with run flats (Conti Sportcontact SSR). I'm going to need new fronts soon. My local tyre place asked me if I wanted to keep the run flats - I've not had a car tyre puncture in 20 years, and I can do a roadside repair if I ever get one, so I'm not that bovvered about keeping them, esp. as they are known for creating a harsher ride. However I'm only looking to swap the front tyres at the mo, and that seems to be OK... (as in I don't have to replace the rears at the same time if I move to 'flats').

Google searches suggest that some policies explicitly forbid cars with OEM run flats moving to flats. My current policy does not, but obviously does want to know about modifications. It's clearly not a cosmetic change, could it be classed as a change in performance. That feels like a stretch..., I'll keep the same speed rating (Y) and 'quality' of tyre (i.e. premium)?

Has anyone had experience of this?

 

[KMAC77]

I’ve not heard of anything like that. Then again I don’t look in that much detail. I’ve had run flats for the last 10 years, the last 6 BMW SUV. I can imagine for heavier SUVs there might bd a possible issue in insurers eyes, but a saloon or coupe won’t be as heavy or unwieldy with a flat tyre.

 

[Flyingscotsman]

Probably best to tell them in any case. Can't see that it makes major difference to performance, except perhaps in case of wheel damage from running flat. In that case they might refuse or reduce a claim.

 

[Gillies O'Bryan-Tear]

I’ve not heard of anything like that. Then again I don’t look in that much detail. I’ve had run flats for the last 10 years, the last 6 BMW SUV. I can imagine for heavier SUVs there might bd a possible issue in insurers eyes, but a saloon or coupe won’t be as heavy or unwieldy with a flat tyre.

I don’t see how they’d find out either. I’ve never know insurance company ask about the tyres.

I havel heard Complaints about the run flats - I have them too on my 540. They seem to wear differentially even if tracking is perfect, and some people complain they don’t last long as a consequence.

 

[KMAC77]

I noticed a massive difference in how strong the sidewalls where on my 4 series 19inch wheels to my X4 21s. The sidewalls on the 22s seem really flexible and it showed when I had a complete deflation and the wheel was wrecked due to that. I only drove about 200 metres and the run flat didn’t do its job for me.

 

[RickS1K]

That's an interesting point (and unfortunate experience) KMAC - the whole point of the strengthened sidewall is to allow the car to drive after a puncture...and that infers that it should stay strong and prevent wheel damage.

If I compare even the RF and non-RF version of the tyres I have now (Conti Sportcontact 5) the EU ratings are better for the non RF (C/A/71 vs D/B/71 - Rain / Economy / db), I didn't realise that the RFs were quite so bad, esp in the wet.

The next Q I need to work out is if I can leave the RFs on the rear if I change the fronts, as they have lots of life left - seems to be differences in advice on that. There do appear to be other tyres that perform much better all round.

btw I did call my insurance company and they said that I DO need to inform them if I fit non-RF tyres, but that 'there might not be any change in the premium'. I was going to explore that last statement with them, but the call dropped, haven't called back yet.

 

[MrSmooth]

Colin, how much do you really save by not fitting RF tyres?

My wife has a Boxster 718S, the Porsche manual says that she can run for 50km at 80km/h if she gets a flat tyre, enough to get her to the next junction on a motorway. I checked the tyre on Pirelli website and it says that it is indeed a RF tyre. When I rang Porsche to book it in for a pair of replacement tyres to be fitted after a catastrophic failure, because you can't fit just one tyre (thanks Hants CC for your fecking pothole and then denying all responsibility for it, their bastard Highways dept can Rot in Feckin Hell). I asked the Porsche service man whether they would be the same as the original fitted Pirelli tyres, which are RF. "No Sir, the Porsche Pirelli tyres were never RF....?????"

How does that work? The tyre manufacturer says they are RF, the Porsche manual insists that you can run them for 50km at speeds approaching 80km/h which implies that they are RF, yet they aren't described as RF by the Porsche dealer?

I got them fitted by my local Pirelli authorised tyre specialist, who also fitted the correct Porsche approved Porsche tyre pressure valve sensor, saved myself £200 for the same pair of tyres.....

 

[RickS1K]

This isn't really a money thing Steve, just interested in exploring alternatives.
Correction, it was just an idea.. until I saw how bad my tyres are (comparatively) in the wet confirmed what I already thought.

 

[alex]

Run flats are horrific lumps of plastic. Ruin ride and handling.