Mixing runflats and non run flats - Problems??

[Neil_W]

Hello all


Hope you have had a good Christmas?

I have decided to move away from run flats for obvious reasons, the problem I have is my rears needed changing and my fronts still had about 5mm of treat on.

I didnt want to waste good tyres on the front so ony changed the backs to Toyo T1R's, the fitter warned me that handling might be a bit twitchy cus iv mixed the tyres, not sure if he was just saying that to get me to buy more though?

I have had a few twitchy moments and not sure if thats just due to the weather or the tyres?

Anyone got any ideas?

neil

 

[Neil_W]

Also can anyone recomend a tyre spray thing to fix flat tyres if I get one on my none run flat. I was told there was one specific brand that could be cleaned out so the tyre could still be repaired....

 

[PawnSacrifice]

I would always have matching tyres all round, but I don't think it's dangerous, others disagree, but in the nanny state word we live in it's not a legal requirement. The handling will be ultimately compromised with mixed tyres and you need to keep the same across the axel (which it sounds like you have done) - think Michelin have that on their web site, they don't say all 4 must the same, but I would get there as soon as possible

You should consider taking the fronts off and trying to sell them part worn, have a look and see what you'd get back... 5mm will last an age with RFTs.

Reference the tyre goo, this thread may help...
Non Runflat Tyres (RFT) Options for a puncture

Only thing I would add, with the mixed tyres, make sure you get to learn what the car is doing at each end (under/oversteer) before pressing on, especially if you turn off the driver aids - which I imagine will compensate for everyday difference in grip.

 

[Neil_W]

Cheers mate, clears that up nicely - Might try and sell the tyres the T1R's are only £80 a corner so even if I made £50 wouldnt cost that much to sort

 

[PawnSacrifice]

Here's the safety info from Michelin, even then it relates to Radial and Non Radial...

NEVER MIX RADIAL AND NON RADIAL TYRES
Do not mix radial and non-radial (i.e. cross-ply or bias-belted) tyres on a vehicle. If mixing tyres is unavoidable, never mix radial and non-radial tyres on the same axle. If two radial and two non-radial tyres are installed on a vehicle, the two radials must be installed on the rear axle and the two non-radials on the front axle.

Source: When should I change my tyres?

To add...

Radial tyres (even when new) must always be fitted on the rear axle; winter or studded must fitted in complete sets

Source: Ten Commandments for Preventive Maintenance

That is all that is mentioned about mixing tyres - Goodyear and Dunlop have nothing on their web sites, that I could find anyway.

 

[cj10jeeper]

I fall into the 'don't do it' camp on mixed RFT and normal and would never drive a performance car on such a mix.

Under normal driving and braking conditions you'll notice very little difference as the axles will still be balanced. Where the problem arises is on the limit when suddenly the different sidewall and grip characteristics cut in. That could induce serious over or understeer just when least expected.

Of course you can drive 1000's miles as some have and it'll make no difference and I fully understand the desire to keep costs down, but explain it to old bill if something happens.

Frankly I'd get a set of 4, sell the RFT's as spares as there is a ready market and get 4 new matched tread and type of tyres.

 

[lacroupade]

Here's the safety info from Michelin, even then it relates to Radial and Non Radial...

NEVER MIX RADIAL AND NON RADIAL TYRES
Do not mix radial and non-radial (i.e. cross-ply or bias-belted) tyres on a vehicle. If mixing tyres is unavoidable, never mix radial and non-radial tyres on the same axle. If two radial and two non-radial tyres are installed on a vehicle, the two radials must be installed on the rear axle and the two non-radials on the front axle.

Source: When should I change my tyres?

To add...

Radial tyres (even when new) must always be fitted on the rear axle; winter or studded must fitted in complete sets

Source: Ten Commandments for Preventive Maintenance

That is all that is mentioned about mixing tyres - Goodyear and Dunlop have nothing on their web sites, that I could find anyway.

Is that off a 1970s retro site or something? LMAO...cross-ply tyres? oke: :rofl:

 

[srhutch]

Not worth the risk, last thing you want is insurance issues if you have mixed tyres.

You have told your insurance company you have removed the runflats haven't you?

 

[lacroupade]

Not worth the risk, last thing you want is insurance issues if you have mixed tyres.

You have told your insurance company you have removed the runflats haven't you?

and the latest documented instance of an insurance company refusing to pay out because of such a change is...........? :fuelfire:

 

[lacroupade]

..and while we are at it, lets just put this thread in some context shall we?

Its absolutely not illegal to mix RFTs/NonRFTs between front and rear axles. "The Industry" would say "not recommended" wouldn't they. Just ask our US friends about product liability - thats why they respond in such a fashion, no other reason. If it was clearly dangerous it would be illegal, MoT failure etc..etc. - but it isn't.

And frankly, for it to become a credible safety issue I suspect you'd have to be driving the vehicle waaaaaay beyond whats legal - so unless the OP is planning a track day or something, I for one would say JFDI.

 

[srhutch]

Not worth the risk, last thing you want is insurance issues if you have mixed tyres.

You have told your insurance company you have removed the runflats haven't you?

and the latest documented instance of an insurance company refusing to pay out because of such a change is...........? :fuelfire:

It is classed as a modification so your insurance company must be informed.

 

[cj10jeeper]

..and while we are at it, lets just put this thread in some context shall we?

Its absolutely not illegal to mix RFTs/NonRFTs between front and rear axles. "The Industry" would say "not recommended" wouldn't they. Just ask our US friends about product liability - thats why they respond in such a fashion, no other reason. If it was clearly dangerous it would be illegal, MoT failure etc..etc. - but it isn't.

And frankly, for it to become a credible safety issue I suspect you'd have to be driving the vehicle waaaaaay beyond whats legal - so unless the OP is planning a track day or something, I for one would say JFDI.

'JFDI' - You're excitable tonight oke:


Our Uk laws are laughable VS the EU, hence most of Europe's trashed tyres end up in back street garages being sold as p'art worns' as we allow it :thumbsdown:
Equaly our laws are just behind the times. We take no account of Winter and Summer mixes, different brands on axles, etc. just radial/crossply that was really a 1960's changeover.

Such mixes are illegal in France though:

Obligations légales

Depuis 1995, le Code de la Route impose les règles suivantes :


Il est interdit de monter sur les véhicules automobiles et leurs remorques :

* des pneumatiques de structures différentes, à l'exclusion de l'éventuel pneumatique de secours à usage temporaire ;
* des pneumatiques de types différents sur un même essieu, qu'il soit à roues simples ou à roues jumelées ;
* des pneumatiques sur lesquels figurent un indice de capacité de charge ou un symbole de catégorie de vitesse inférieurs aux capacités maximales prévues par le constructeur du véhicule.

First * line is not axle specific, second line even makes different makes ont he same axle illegal.

Anyway a call to the insurer - explain the situation of mixing would clarify their view of it. I bet I know the answer - not covered.

 

[PawnSacrifice]

EDIT: Ha, have been playing CoD, see things have moved on before I wrote...

lacroupade, yeah, well... it's the US site!

I'm going to stop with why I don't think it's as bad as everyone else because the fact is, 4 matched tyres is ideal. If only we had roads where they were all on the same surface at the same time :roll:

The other thing I was going to argue was the benefit of driver aids, it occurred to me that is the second argument against mixed tyres front and rear - it'll be working / cutting in more and sapping the fun.

Oddly, for an M, I would staunchly advocate matched on all corners, no excuses, no exception.

EDIT: CJ, that's interesting about Europe. I do think the winter tyre laws are one we should look at - not for the snow, but mine are so much better at 3 degrees and below. Contentious but I think there's a greater risk driving in low temperatures with standard tyres than there is of mixing on axels under normal conditions. I think the danger isn't with the snow and ice, that's practicality, but with low temperatures where people still feel safe and probably don't realise negative affect it has on the tyres.

 

[WLH]

Contentious but I think there's a greater risk driving in low temperatures with standard tyres than there is of mixing on axels under normal conditions. I think the danger isn't with the snow and ice, that's practicality, but with low temperatures where people still feel safe and probably don't realise negative affect it has on the tyres.

I agree...

 

[lacroupade]

..and while we are at it, lets just put this thread in some context shall we?

Its absolutely not illegal to mix RFTs/NonRFTs between front and rear axles. "The Industry" would say "not recommended" wouldn't they. Just ask our US friends about product liability - thats why they respond in such a fashion, no other reason. If it was clearly dangerous it would be illegal, MoT failure etc..etc. - but it isn't.

And frankly, for it to become a credible safety issue I suspect you'd have to be driving the vehicle waaaaaay beyond whats legal - so unless the OP is planning a track day or something, I for one would say JFDI.

'JFDI' - You're excitable tonight oke:

LMAO!!! Yes I was in one wasn't I ,probably comes from spending too much time on 4x4 sites listening to people who think its marvellous to swap their stats from 88 to 82 and back again twice a year :headbang:

But in all seriousness my point was that we can all get a but too carried away and PC at times and this was one of those occasions where lifes just too short so live dangerously for once.

And I would never advise my insurance company aout a change of tyres like that. I mean running winter tyres is a mod isn't it, do we tell them that too? I mean if you left them on when it got a bit warm that soft compound would change driving characteristics just as much as RFT/non-RFT.....

The essence of it is these blood-sucking leeches get enough of my time and money as it is so I'm quite happy to make an informed decision and not bother telling them. If I lost out on an insurance claim as a result then I take the rap, but somehow I seriously doubt they'd have a case. Look forward to seeing my name in the papers! :rofl:

 

[AlanJ]

I fall into the 'don't do it' camp on mixed RFT and normal and would never drive a performance car on such a mix.

Under normal driving and braking conditions you'll notice very little difference as the axles will still be balanced. Where the problem arises is on the limit when suddenly the different sidewall and grip characteristics cut in. That could induce serious over or understeer just when least expected.

Of course you can drive 1000's miles as some have and it'll make no difference and I fully understand the desire to keep costs down, but explain it to old bill if something happens.

Frankly I'd get a set of 4, sell the RFT's as spares as there is a ready market and get 4 new matched tread and type of tyres.

AGree with CJ - tell your insurance company after an accident that you've got mixed tyres on front and rear and see what they say..... better still ask them before you do it. I know what the answer will be... :thumbsdown:

 

[Siftah]

AGree with CJ - tell your insurance company after an accident that you've got mixed tyres on front and rear and see what they say..... better still ask them before you do it. I know what the answer will be... :thumbsdown:

You'd never tell them that, they'd have to spot it themselves.

Plus, if they did spot it and queried it, then you're not breaking the law so they'd struggle to halt the claim because of it. It would have to be specifically stated in the T&C's you signed when you took out the insurance for them to have a hope in hell of making it stick.

I'd love to hear from someone who's actually had this happen to them, first hand...

 

[cj10jeeper]

AGree with CJ - tell your insurance company after an accident that you've got mixed tyres on front and rear and see what they say..... better still ask them before you do it. I know what the answer will be... :thumbsdown:

You'd never tell them that, they'd have to spot it themselves.

Plus, if they did spot it and queried it, then you're not breaking the law so they'd struggle to halt the claim because of it. It would have to be specifically stated in the T&C's you signed when you took out the insurance for them to have a hope in hell of making it stick.

I'd love to hear from someone who's actually had this happen to them, first hand...

This has moved more to one of those theoretical discussions, so almost now unrelated to if driving on mixed tyres matters, however the onus is in all policies for the policy holder to declare anything material to the insurance company. If there is any doubt the onus remains to declare it. Swapping some or all tyres to non RFT clearly falls in that category. Been discussed enough times and many have posted insurer responses. Some don't care others note the change, etc.

Having been involved in one major accident in my life where a moped riding teenager without a helmet decided to slide under my car (thankfully just lived) I can tell you the length insurers go to. My car (brand new) was taken to a special centre and inspected for the slightest fault. The report contained make, type of tyre, tread, brake test report. Steering set up, an on an on and on. I have no doubt if they could have found something it would have been used to somehow defend a lets just say massive claim.

 

[Siftah]

This has moved more to one of those theoretical discussions, so almost now unrelated to if driving on mixed tyres matters, however the onus is in all policies for the policy holder to declare anything material to the insurance company. If there is any doubt the onus remains to declare it. Swapping some or all tyres to non RFT clearly falls in that category. Been discussed enough times and many have posted insurer responses. Some don't care others note the change, etc.

Having been involved in one major accident in my life where a moped riding teenager without a helmet decided to slide under my car (thankfully just lived) I can tell you the length insurers go to. My car (brand new) was taken to a special centre and inspected for the slightest fault. The report contained make, type of tyre, tread, brake test report. Steering set up, an on an on and on. I have no doubt if they could have found something it would have been used to somehow defend a lets just say massive claim.

True, it's going to depend heavily on the extent of the claim as to whether they investigate the car. I'd be *very* surprised if they could use it to wriggle out of a claim though, I'd be surprised if the insurance ombudsmen would let that slip.

They'll always try to wriggle out of a claim, you have to be persistent with them, get your own solicitor rather than using theirs so you have someone fighting on your behalf.

 

[AlanJ]

It's not a case of wriggling out of a claim but potentially reducing the final settlement due to a fault by the owner of failing to notify a modification. Insurance policies are based on a calculated risk - vary that risk during the life of the policy and then the problems start.