TYRE SIZES.

[alfiestock]

Hello all I am looking for advice regarding what the legalities are concerning tyre sizes, I purchased a 3 year old vehicle from a main dealer 8 months ago and recently had a puncture, the garage that repaired the tyre informed me lol the tyre on the car were 245/ 18 and should be 255/18 as in the vehicle handbook. I spoke to salesman about this and his reply was it is not a major problem ! Any advice from forum welcome..

[SonicShadow]

Are the tyres the same size across each axle? If so, it's not a major problem. Some AWD systems won't like different sizes front and rear.

[P I Staker]

It's not a major problem.

[Vaud]

Some handbooks give a range of tyres that can be used - what does yours say?

[kambites]

It's certainly not a major problem from the point of view of how the car will drive (as long as the tyres are all that size). Your insurers might class it as a "modification" though, if it's not a standard sized tyre for that model?

[alfiestock]

Thanks for the advice I am just looking for assurances that in the event of an insurance issue the tyre sizes would not be a problem...

[P I Staker]

alfiestock said:

Thanks for the advice I am just looking for assurances that in the event of an insurance issue the tyre sizes would not be a problem...

Ask your insurance company.

[alfiestock]

Thanks for the advice I am just looking for assurances that in the event of an insurance issue the tyre sizes would not be a problem...

[Claudia Skies]

The best way to get that "assurance" is to talk to your insurance company.

[McSam]

Another consideration is that the rolling radius of the tyres may be different to what the car was designed for. You haven't posted the full size code, just the section width and the rim size, but the number in between - called the aspect ratio - is also important. This is what determines how "high" the tyre is.

Effects of using tyres with the incorrect rolling radius will be a change in ride height, altered gearing if on the drive wheels, and incorrect speedometer reading if on the wheels used for that.