Stretched Tyres - legal or not ? Discuss

[garrardrj]

Topic on Edition38 i have got involved in ! A chap has been summoned to court and being an ex officer i cannot find anything about it specifically , there are construction and use regs that cover issues with all sorts of running gear but any comment from this forum ?

[Nodz]

As long as the tyres are used within manufacturers specifications there shouldn't be an issue. I would assume some stretch would be ok but surely a lot of stretch would alter the the load the tyre could take and change the speed rating etc as they are not being fitted the way the manufacturer of the tyre has stated or tested. It's grey area really.

[Horatio]

A quick google threw up this thread from here from 2006 http://www.ukpoliceonline.co.uk/index.php?/topic/24937-stretched-tyres-are-they-legal-or-not/

Could actually set a precedent  be interesting to know the outcome. I guess if the tyre is not being used for what its designed to do, it will be construed as dangerous.

[xjay1337]

Stretch is not illegal.
However there are construction and use regulations. Tyre manufacturers state that certain tyre sizes can be fitted to certain size rims. EG:

Tyre Size: 225/40/18
Allowed wheel sizes : 7.5 to 8.5

This is all documented and available on each tyre manufacturers website.
You can fit tyres to the wheel widths specified by those "legally".
So if Falken (for example) say you can put 225/40 on a 9.5 inch wheel, then that is completely legal and you are completely within your right to do so. However, put it on a 10 inch wheel and you're screwed..

With regards to poke you can have a maximum of 30mm out from the most outer part of the wheel arch, the sidewall can be exposed however the TREAD must be covered by the wheel arch.

In the real world, due to different tyres running different actual width, you may find that some tyres stretch less... so I had 215/35 on my Mercedes wheels, which are 8.5 inches wide. I still have a rim protector....
So I am very unlikely to have it questioned by police officers in the event on a stop, as the tyres don't look out of place. However if they were so inclined they could pick up on it.. But as the stretch was sensible and not visually excessive, it's one of those things..

[DDM]

Stretch is not illegal.
However there are construction and use regulations. Tyre manufacturers state that certain tyre sizes can be fitted to certain size rims. EG:

Tyre Size: 225/40/18
Allowed wheel sizes : 7.5 to 8.5

This is all documented and available on each tyre manufacturers website.
You can fit tyres to the wheel widths specified by those "legally".
So if Falken (for example) say you can put 225/40 on a 9.5 inch wheel, then that is completely legal and you are completely within your right to do so. However, put it on a 10 inch wheel and you're screwed..

With regards to poke you can have a maximum of 30mm out from the most outer part of the wheel arch, the sidewall can be exposed however the TREAD must be covered by the wheel arch.

In the real world, due to different tyres running different actual width, you may find that some tyres stretch less... so I had 215/35 on my Mercedes wheels, which are 8.5 inches wide. I still have a rim protector....
So I am very unlikely to have it questioned by police officers in the event on a stop, as the tyres don't look out of place. However if they were so inclined they could pick up on it.. But as the stretch was sensible and not visually excessive, it's one of those things..

wouldn't the tyre manufacturers only be able to recommend the tyre size to the rim width, rather than make it a legal statement that someone could use in their defence?

[Dan_FR]

Tyre manufacturers advice isn't law, but using a tyre outside of their recommendation can be deemed to contravene the Construction and Use regs. Has anyone got a link to the thread in question?

[xjay1337]

wouldn't the tyre manufacturers only be able to recommend the tyre size to the rim width, rather than make it a legal statement that someone could use in their defence?

No, you are fitting tyres in accordance with the manufactures guidelines, which form up part of the construction and usage regulations.

[Viking]

What about the wheel manufacturers (or more specifically, the car manufacturers) recommendations? VW specify a certain speed rating, load rating, size, etc. for the car, and would it not contravene the construction & use regulations if tyres outside of their recommendations were fitted to the wheels on the car? And whilst not perhaps being strictly legal or illegal, if your insurers remove cover for deviating from the manufacturers spec wouldn't that result in a summons for driving without insurance?

Of course, if you tell your insurers before you deviate from manufacturers spec, then that window of opportunity is denied to the police.

[xjay1337]

What about the wheel manufacturers (or more specifically, the car manufacturers) recommendations? VW specify a certain speed rating, load rating, size, etc. for the car, and would it not contravene the construction & use regulations if tyres outside of their recommendations were fitted to the wheels on the car? And whilst not perhaps being strictly legal or illegal, if your insurers remove cover for deviating from the manufacturers spec wouldn't that result in a summons for driving without insurance?

Of course, if you tell your insurers before you deviate from manufacturers spec, then that window of opportunity is denied to the police.

I don't see the point of what you said. 

We all know about fitting the correct speed rating of tyre. Once a car has left the factory you are free to change your wheels and tyres as you deem fit. I've never read anything that says you have to fit certain width wheels to a car.. only factory stickers saying here's the factory fit tyre sizes and their relevant pressures (which are invariably the same anyway!  )

Also being insured and being legal are very different... my insurance are aware of my Decat but it's still illegal....

[Viking]

What about the wheel manufacturers (or more specifically, the car manufacturers) recommendations? VW specify a certain speed rating, load rating, size, etc. for the car, and would it not contravene the construction & use regulations if tyres outside of their recommendations were fitted to the wheels on the car? And whilst not perhaps being strictly legal or illegal, if your insurers remove cover for deviating from the manufacturers spec wouldn't that result in a summons for driving without insurance?

Of course, if you tell your insurers before you deviate from manufacturers spec, then that window of opportunity is denied to the police.

I don't see the point of what you said. 

We all know about fitting the correct speed rating of tyre. Once a car has left the factory you are free to change your wheels and tyres as you deem fit. I've never read anything that says you have to fit certain width wheels to a car.. only factory stickers saying here's the factory fit tyre sizes and their relevant pressures (which are invariably the same anyway!  )

Also being insured and being legal are very different... my insurance are aware of my Decat but it's still illegal....

The vehicle is type approved with specific wheels and tyres fitted. That approval would be part of the construction and use regulations I suspect. Changing the tyre sizes on the wheels outside of the car manufacturers specifications would therefore contravene those C&U regs. My point being that you can't simply quote the tyre manufacturers recommendations and specifications and say that you're okay, while singularly ignoring the car manufacturers specifications.

[Nodz]

So going by that if you  put different aftermarket wheels on as it would contravene the regs then also implying that any modification to the vehicle would contravene the regs as I would expect virtually everything on a car is type approved.

[Viking]

In theory, yes. However, people still do so. However, changing a set of wheels for a different set of wheels is less likely to cause issues with the police than fitting tyres which are too small for the wheels. But as is widely known, changing wheels from standard fit is also insurance notifiable, which brings you back to the point Jay made (sort of), where the change is entirely acceptable to the insurers but is in contravention of the regulations.

Still, if someone is going before the Courts due to being stopped using stretched tyres, we'll have a definitive answer sometime soon as to the legality of doing so.

[Nodz]

So not touching on the insurance part as we all know any modification is notifiable.

The tyres have obviously had to go through some sort of type approval so as long as they meet the construction and use regs then. As long as everything you fit is designed for the purpose and you have notified your insurance I cant see there being an issue.

A car with a decat will fail on emission, so running it either side of an MOT as a get around wouldnt work as VOSA could declare it unroad worthy. With tyres as long as the tyres are fitted to tyre manufacturers spec and have the correct legal markings on them for uk use, have the tread tucked in the arches with legal poke and camber I cannot see how they could prosecute.

[Viking]

See, everyone is all banging on about the tyres and their specification. My point is that the tyres are fitted to a car and the car manufacturers spec can't just be ignored as people see fit. Not saying it's right or wrong, but if Loon does get to Court and the Police officer pulls out that they tyres are fitted outside of the car manufacturers specification, then all the groundwork pulling in tyre specifications will not be worth the paper it's written on.

We'll have to wait and see what happens.

[Nodz]

See, everyone is all banging on about the tyres and their specification. My point is that the tyres are fitted to a car and the car manufacturers spec can't just be ignored as people see fit. Not saying it's right or wrong, but if Loon does get to Court and the Police officer pulls out that they tyres are fitted outside of the car manufacturers specification, then all the groundwork pulling in tyre specifications will not be worth the paper it's written on.

We'll have to wait and see what happens.

But then all aftermarket wheels fitted to a gti require to be 7.5j or they wont meet car manufacturers spec meaning anyone running any other width wheel are outside the car  manufacturers spec. As would any other diameter wheels that are not 17" or 18". You could then go into lowering springs etc etc.