Fitting a different size of tyre?
- Thread starter marl
- Start date
![[TW]Fox](/data/man-of-honor/2009.png){kind=avatar}
Associate
- Joined
- 15 Jun 2009
- Posts
- 2,494
They'll fit, but your speedo will be off by about 3% as the new tyres are bigger.
- Joined
- 14 Jun 2004
- Posts
- 17,528
- Location
- Newcastle U/T
And remember to notify your insurance
Man of Honour
- Joined
- 17 Nov 2003
- Posts
- 36,747
- Location
- Southampton, UK
What?
Wouldn't they be classed as a modification from standard ?
Not this again...
Why would you declare tyres?
Other than fitting any kind of track focused semi slicks (e.g. R888's), then I wouldn't bother. I wouldn't even declare winter tyres, unless the policy mentioned them, or you were fitting different size wheels.
Insurers have no knowledge of what tyre should be on the car (given that tyres from different oems can be used on the same model, depending on availability etc). If you bought a car second hand, how would you know what tyres were originally on it?
Might as well declare my air freshener next time I speak to my insurance company.
Calculator here shows 2mph difference @ 60mph
http://tire-size-conversion.com/speedometer-calibration/
Associate
- Joined
- 14 Jul 2004
- Posts
- 1,465
- Location
- Caerphilly - S.Wales
Same issue we have, although we have 195/45/16 think will just get good s ummer tyres. Do like the idea of the Cross Climate though.
A quick look at Blackcircles - I would think Michelin Pilot Sport 3's are probably the best option in that size
That's about 3%.
Soldato
- Joined
- 25 May 2008
- Posts
- 3,983
- Location
- North Wales
I'd not be worried about going a size either way as in the real world there will be pretty much no difference, i've gone from 215/45/17 -> 225/45/17 and 205/50/16 -> 205/55/16 on cars over the years.
- Joined
- 14 Jun 2004
- Posts
- 17,528
- Location
- Newcastle U/T
Well thats one declaration I'll no longer be making then, might drop my premium haha 
Appears as long as the speed/load rating are correct then all's good.
Seems the biggest change is going from run-flats to non run flats and there only a couple of insurers that care about that now too:
https://www.abi.org.uk/~/media/File...nter tyres The motor insurance commitment.pdf
Think I'm just gonna start and ignore everythign that admiral tell me lol
As for tyres, tyreleader has Uniroyal Rainsport 3's in your size for £47.49
Going by their branded specification should be the same other than a little more road noise well that and you'd save over £20 a corner
Appears as long as the speed/load rating are correct then all's good.
Seems the biggest change is going from run-flats to non run flats and there only a couple of insurers that care about that now too:
https://www.abi.org.uk/~/media/File...nter tyres The motor insurance commitment.pdf
Think I'm just gonna start and ignore everythign that admiral tell me lol
As for tyres, tyreleader has Uniroyal Rainsport 3's in your size for £47.49
Going by their branded specification should be the same other than a little more road noise well that and you'd save over £20 a corner
Associate
- Joined
- 23 Oct 2013
- Posts
- 1,244
are you serious? What does the car's handbook say? that will specify what tyre sizes are expected on the car (and there's usually also a little sticker around the door/frame somewhere). Any size in that list is fine, not a mod, as it's a factory approved size, anything else is a change from factory spec thus a mod. If a crash/insurance investigator has the skills to work out if there are any problems with the car prior to a crash, then it's not beyond their skill to look at the tyres and the little sticker and notice any difference...
Whether it makes any financial difference to your insurance, probably not, but it's still technically a mod.
*edit* and to think that in an accident they wouldn't check the tyres is potential lunacy. Obviously tread/wear is checked, but surely they'll also check tyre sizes, if only to ensure some muppet hasn't put a different size tyre on the same axle...
In some respects I also don't understand why you think this can easily happen unknowingly. Car owners with no knowledge of tyre sizes will just get whatever the garage says, so "should" be standard size. So this only really happens when a car owner purposely goes against the standard spec knowingly, so there's little room to argue they didn't know it wasn't the original size and therefore shouldn't disclose it. (yeah, sure, unless you buy the car 2nd hand and it was like it - which is why car insurance is worded something like "to the best of my knowledge" - but, if you've had the car a year and replaced tyres 6 months ago, then you really "should" be expected to check the handbook/sticker/garage for the stock size, so the "it came like that when I bought it" excuse can't run indefinitely)
Last edited:
Well I actually meant in regards to changing brands, but since you've now gone off on one...
No guarantee I have one.
Being picky - as above, may have been removed if the car has been repaired/repainted.
Clearly not, because if my for example my car was an SE spec Audi (16" Wheels) and I changed to S-Line alloys (18" wheels), just because the tyres size is on the factory list doesn't mean it's not a mod - it has potentially changed the value of the car/made it more desirable, therefore changing the insurance risk and needing to be declared.
Never said they wouldn't be checked - but tread/wear and obvious defects will be the main thing checked. Lots of people still think it's fine to drive round with 4 mismatched tyres, never heard of any insurance issues with that - and it's far more of a risk.
Nope - everyone I know when ordering tyres checks the ratings on the side of their current tyres and quotes that for any website or when speaking to a tyre fitter.
90% of the population don't care whether their tyres are linglongs or whatever, as long as they are legal, what makes you think they do any more than just reorder based on what is on the car already.
As above, maybe car didn't come with book. Maybe the car came with aftermarket wheels that look standard or are from another model within the manufacturer group (e.g. VW wheels on an Audi) - they look standard, how do I as a second hand buyer know they are not the original wheels? (i.e. I wouldn't even declare them unless they were obviously aftermarket).
Maybe the wheels tyres were a dealer option and differ from the factory spec (e.g. thinking "approved tuners" like AC Schnitzer, Alpina, AMG etc).
What about if I fit non "N-marked" tyres to a Porsche - do I need to declare that?
Will ring my Insurance later and declare my air freshener - wouldn't want it swinging around and being a contributing factor that I hadn't declared.