[xenon]

Perhaps. I would argue that run-flats are an additional convinience to the driver (an optional extra) and the 3 series can be specified with conventional or RFT options from new. As long as the tyre's speed rating and load index were at or above the original equipment I can't see how they could legitimately refuse cover.

Regarding the mixing, I agree that it should not be done and thanks for the link.

[gIzzE]

Originally Posted by xenon

Perhaps. I would argue that run-flats are an additional convinience to the driver (an optional extra) and the 3 series can be specified with conventional or RFT options from new. As long as the tyre's speed rating and load index were at or above the original equipment I can't see how they could legitimately refuse cover.

Regarding the mixing, I agree that it should not be done and thanks for the link.

You can argue all you like with them mate, if you win you get paid out, if you loose you loose the value of your car.

I have always called my insurer when ditching run flats when I know it was supplied from new with them, just to make sure I am covered.
There has never been a problem with it, but I just want to make sure if anything happens they are not going to wriggle out by saying I had fitted incorrect tyres.
I say that, swiftcover wouldn't let me swap, so I swapped insurer, it was like talking to a bunch of idiots, they just couldn't do anything that was not in the manual in front of them.

[xenon]

The ombudsman would uphold the argument I'm sure.

Still, I'm not saying one shouldn't be on the safe side but I never gave it a second though. As long as I had W rated tyres and 94 load index then they're approved by the manufacturer. You can get a 3 series without RFTs after all.

[gIzzE]

Originally Posted by xenon

The ombudsman would uphold the argument I'm sure.

If you're not that worried about it why ask if there is anywhere that states that mixing tyres would invalidate your insurance?
All I am saying is if you are concerned a 30 second phone call to your insurer 100% covers you.

[xenon]

I seem to be getting in to an argument when I fully agree with you. I just wondered if it was documented. Anyway - that's mixing tyres (the statement on the website) and the conversation moved on to a full replecement. As far as I'm concerned a full replacement of all four tyres of a specification at or above the manufacturer's specifications is legitimate, be they RFT or otherwise.

[gIzzE]

It's not an argument, I just pointed out that changing from run flats is still seen as a 'no no' by some insurers, therefore it really isn't worth risking not making that 30 second call.

I wish insurance companies weren't assholes, and the majority are OK, however, I do think you have to cover your own ass with stuff like this.

[xenon]

Fair comment.

[HighlandPete]

Originally Posted by xenon

As a point of interest has anyone got a link to something authoritative which says they must not be mixed?

Yes the statement is out there all over the industry, tyre companies Continental, Pirelli... Also the industry bodies like TyreSafe, Tyre Council, etc.

I've often added direct links and quotes, really been done to death over the years.

If you want the links, I'll see what I've got archived.

The quotes are typical of what you'll find, for some reason I haven't got which sources for these from a quick Word search. But I do believe the first one is from Continental from the SSR reference.

An SSR/standard tyre mix should not be fitted on a vehicle – not even axlewise.(In isolated cases a standard tyre can be temporarily mounted on a vehicle otherwise equipped with SSR tyres. It must be pointed out to the driver, however, that the standard tyre has no runflat properties.)

Run-flat tyres, or self supporting run-flat tyres to give them their correct title, should not be fitted to a vehicle not designed to accept them or without a pressure monitoring system. Equally they should not be mixed with conventional tyres as the handling and performance characteristics of the two types of tyres are quite different. Mixing of different brands of SST tyres may also not be advisable and the motorist should check with the manufacturer of the tyre or vehicle for advice. It is recommended that the same make and type of SST tyre be fitted across the same axle.

HighlandPete

[xenon]

Thanks Pete - don't bother checking back for links. Whilst it would obviously be sensible not to mix I wondered if there was any hard evidence which there evidently is.

[creepy coupe]

I'd really like to know, what is so bad about mixing them? although I can see mixing on the same axle might lead to the ride feeling strange, but on different axles, how bad can it be?

[gIzzE]

Mixing treads or RFTs??

An asymmetrical tread is designed to grip less but communicate what is going on underneath you far better than a symmetrical tyre, which doesn't give the feedback but can grip at higher speeds, problem is when it lets go it snaps and is harder to control.

You then get different compounds, a softer compound will also bite in more but is harder to control, a harder compound will not grip as well but easier to control if the back end does skip out.

Put an asymmetrical on the back of a fwd car like an Audi and it can help reduce understeer, put a much harder compound asymmetrical on the back of it and it can help even more. But with a BMW which is RWD and tends to oversteer this can be a very bad thing, you can make the back end very, very twitchy, go into a corner fast and the front end grips but the back wants to slide round, not expecting it and you may find you're off the road.


It is all basic physics.

[HighlandPete]

Originally Posted by creepy coupe

I'd really like to know, what is so bad about mixing them? although I can see mixing on the same axle might lead to the ride feeling strange, but on different axles, how bad can it be?

This may be an extreme example, but I come from the era when you could still legally mix radial and cross ply tyres. The characteristics were so different, disasters happened over and over, until the introduction of the law, which specified radials if fitted in mixed tyre fitments, were rear axle only. Yes, became illegal to have the wrong mix. Many a car had lost it, due to a tyre characteristic which initially wasn't understood.

We may not be at that level of severity, but if evidence comes forward that accidents could be caused by mixing RFTs with non RFTs, we may need the same sort of legislation in the future.

HighlandPete

[Jeff123]

I would be interested to know if anyone has had a claim refused for changing from runflats to non-runflats. Many people seem to be wary about the possibility - but has an instance actually occurred?

[gIzzE]

How many people who have swapped have even had an accident bad enough to need their car inspected?

[magic77]

Before I ditched my RFT I spoke to my insruance company the key is if ditching RFTs to swap for identical tyres in terms of size and rating of same or higher index. Then you are fine. According to my insruance at least RFT is more of a convienience than a must. Ie an option of having a can of glue in the boot as other makes have.

I can see benefits of RFTs but not in UK with the terrible roads. In germany where B roads are better than our A roads RFTs do make sense, hopefully over time prices will come down and ride quality will improve then RFTs would make sense.

Right now I cant see the use of them. They make the ride harshers, have been a suspect in the wheel cracking cases, and cost more. Ok if you get a puncture you can drive on it but then it needs to be chucked(unless you can find a tyre shop to fix it - which I have just no local to me) anyhow so dont see it much of a point.

OK if I get a puncture I got to mess around with the can etc, or get receovered to tyre place but then tyre needs repalcing anyway so might as well save the few hundred quid and get normal tyres.

Also when I switched to non RFT the contis I got came as XL (extra load) on the fronts. THus are slightly stiffer than normal so even the feel of the steering hasnt changed that much

[xenon]

Originally Posted by magic77

Before I ditched my RFT I spoke to my insruance company the key is if ditching RFTs to swap for identical tyres in terms of size and rating of same or higher index. Then you are fine. According to my insruance at least RFT is more of a convienience than a must. Ie an option of having a can of glue in the boot as other makes have.

Which was exactly what I was saying. I would not advocate mixing the two types but an entire replacement (as long as the speed rating and load index are sufficient) is fine because you can get an e9x without RFTs from BMW in the first place.

[gIzzE]

Originally Posted by xenon

Which was exactly what I was saying. I would not advocate mixing the two types but an entire replacement (as long as the speed rating and load index are sufficient) is fine because you can get an e9x without RFTs from BMW in the first place.

I agree with all that, but you do need to be aware, there are still some insurers that will play silly buggers, like Swiftcover did with me, and if you have just written your car off the last thing you need is to have to find a solicitor to step in and prove the tyres you swapped should not invalidate your warranty.

While these run flats are still newish I just think you may as well play it safe and cover yourself.
Just look at the fiasco with winter tyres recently, the insurance ombudsman had to step in and say peoples insurance can not be invalidated for having put winter tyres on, some insurers were using them as a get out to not pay.
Even now, winter tyres is fine, but up to the insurer if they are fitted to winter wheels too.

[magic77]

I think as always it will vary from insurnace company to insurnace company.

I found mine to be very good and helpfull in getting clarification on the RFT issue, but I'm sure others would not. Just in same case when few years ago when I colour coded my wifes focus during a body repair. Tesco insurance said no problem no hike in premium its just cosmetic refresh, when renewal came they kept the line and I stuck with them while other firms where trying to charge me for modified "body kit" being fitted. Could not grasp a respray.

When the car finally met an end thanks to a rear impact of 70 mph there where no problems or anything with settlement even after car was inspected it just comes down who you deal with

[ALF_E90]

My view is similar - fit the right sizes and load ratings as per the plate on the car, and it doesn't matter if they are RFT or not as long as the whole set is the same. XL tyres are likely to suit a car set up for RFT tyres better. I don't feel the need to offer extra cash to my insurer for my winter tyres as 225/45/17 94XL all round are on the plate as a standard option, and if I fit non-RFT summer tyres when the current ones wear out (highly likely) I'll just get XL ones of the right sizes all round and again not feel the need to talk to someone in a call centre who has no idea what I'm talking about, but a standard response of "that'll be "£X" extra sir"...