Possible illegal tyre question

I’ve just had all four tyres changed on The Mighty Vectra because the tread was getting a bit borderline. It turns out that I’ve been driving round with one tyre smaller than the other 3! The front left had a 205/55 on it, the rest were 215/55s.

Have I been breaking the law for the last 2 and a bit years?

Have I been invalidating my insurance?

In that time it has got through 3 MOTs without it being picked up and I didn’t notice any tendency to pull to one side.

Tyres need to match in size on an axle by law. I believe it's an MOT requirement, but I'm not going to google for you.

Obviously I'm concerned that my life and the life of my child were in mortal danger when we went to the soft play centre in your deathtrap.

Seems to me you were lucky not to shag your differential.

Seems to me you were lucky not to shag your differential

I once tried that, but couldn't quite reach…

Seems to me you were lucky not to shag your differential.

Open diff I presume unless it's a fancy LSD/viscous setup on that particular model (usually reserved for high end FWD cars), won't give a flying ****. PC plod might.

Seems to me you were lucky not to shag your differential.

What the bloke above said. Won't matter on 90% of cars.

That said, I'm surprised you didn't notice. Even tyres that are mismatched by brand can cause some very odd handling, particularly in the wet. You may find that you can go round corners twice as fas now.

and to think, you were taking the p1ss out of my ghetto 96'er the other week.

Seems to me you were lucky not to shag your differential.

Being as the tyres were the same size in diameter, with only different widths, I'd doubt it made the slightest difference.

Tyres need to match in size on an axle by law

Explain space saver spares then please…..

terrahawk – Member
Obviously I'm concerned that my life and the life of my child were in mortal danger when we went to the soft play centre in your deathtrap.

I'll have to get you another way. My house on Nov 5th… let's blow sh#t up!

molgrips – Member
Seems to me you were lucky not to shag your differential

Let's hope not. I've done 20,000 miles with it like that.

You may find that you can go round corners twice as fas now

YAY!!!

Tyres need to match in size on an axle by law

Explain space saver spares then please…..

I've just had a look. A space saver won't pass the MOT.

I've just had a look. A space saver won't pass the MOT.

I never said it would. But that doesn't make it 'illegal' does it? (As in you'll get nicked for using one)
All an MOT proves it that your car passed certain standards on one day, no more, no less….. 🙂

Being as the tyres were the same size in diameter, with only different widths, I'd doubt it made the slightest difference.

215/55 and 205/55 are different diameters (the 55 is the height expressed as a percentage of the width). Approx 8mm difference between the two. Which would easily be enough to upset some viscous diffs / transfer boxes.

215/55 and 205/55 are different diameters (the 55 is the height expressed as a percentage of the width). Approx 8mm difference between the two. Which would easily be enough to upset some viscous diffs / transfer boxes.

Ahh yes. Fair comment, I was wrong. If I'd had a proper think about it, I'd have realised that. 🙂

Explain space saver spares then please…..

It's an emergency solution and is allowed solely to get you to the nearest garage/tyre place for replacement and at under 55kph, not for general use. It should still be the same diameter as the originals though to maintain brake balance.

Surely you'd need to have two different width wheels to have those tyres fitted?

It's an emergency solution and is allowed solely to get you to the nearest garage/tyre place for replacement and at under 55kph, not for general use. It should still be the same diameter as the originals though to maintain brake balance

Thakyou 🙂

So, to sum up, it's a different size, but not illegal to use. 🙂

Surely you'd need to have two different width wheels to have those tyres fitted?

Nope, 10mm is no problem at all in terms of making the tyre fit. Go and have a look at some of the trendy wendys who've managed to fit 165mm tyres on 8 inch rims at any McDonalds car show.

Who would have thought that my car could generate so much debate!

I'll go and have a look under the driver's seat and report back if I find anything of interest.

Nope, 10mm is no problem at all in terms of making the tyre fit. Go and have a look at some of the trendy wendys who've managed to fit 165mm tyres on 8 inch rims at any McDonalds car show.

I quite like the stretched look, but being keen in the corners I've never been sure I'd like to do it on a performance car!

I quite like the stretched look, but being keen in the corners I've never been sure I'd like to do it on a performance car!

It's a bit of a religious issue on car forums. A while ago I saw a BMW that had been in a fairly minor prang with stretched tyres, and one of them had come off the rim. Not a great advert.

CK – you are a disgrace!

I always think it looks like you spent all your money on wheels and then coundn't afford the right tyres to fit them!

That can't be legal, can it?

Don't the rims/tyres need to be within the wheel arches, i.e not protruding?

That can't be legal, can it?

It's a bit like the mis-matched tyre sizes. It's not explicitly verboten, but you can be sure it's violating construction and use regs somewhere. Certainly a lot of the time a stretched tyre is on a wheel wider than the tyre manufacturer specifies is safe.

CK – you are a disgrace!

hey hey calm down, I did say I've NOT done it because of the function issue outweighing the form issue. Doesn't stop me thinking it looks fairly pleasing 🙂 For that I don't apologise 😀

Don't the rims/tyres need to be within the wheel arches, i.e not protruding?

Not sure on the exact ruling, but I think it must be within the arches, or possibly +1" but no more.

I always think it looks like you spent all your money on wheels and then coundn't afford the right tyres to fit them!

lol, fair point.

It also makes your rims more likely to be dented (lower profile and no sidewall stiffness to resist impacts – bad idea and very expensive. My alloys are chocolate anyway, already flatspotted two of them 🙁