Illegal Tyres?

[George_A_]

Hi everyone,

I have an important question...

My Ford Fiesta Style 1.4 TDCi, was fitted with two types of tyres, the front ones were 195/6015, the rear ones were 185/65X15.

After suffering a flat rear tyre, I took the car to a local "tyre specialist", who told me not only that the tyres of my car were incorrect, but they were illegal to drive, as my speedometer would show incorrect values, because it works on calculating revolutions per minute on the axle, so, a smaller or larger tyre would give different and incorrect values on the speedometer.

He also said that the car should have not passed an MOT with these tyres.

He offered to change all 4 tyres and he fitted on both the front and rear axle some 195/510X15 tyres, which I asked him to do.

I believed what he said, as he offered to write on my invoice that the tyres previously fitted on the car were incorrect, which he has actually done.

As I had bought the car only recently with a full year's MOT, I contacted the car dealer who had sold me the car.

But he replied to me saying that the "tyre specialist" gave me false information and charged me for two extra tyres which were not really needed.

Who is right here?

Thank you in advance everyone,

Kind Regards,

George

[btmaldon]

I don't think it is illegal to have different tyre sizes on front to the rear. If the correct tyre size is on the front the speedo will be correct. The actual circumference for those tyre sizes is only slightly different and if you have the wrong ones on the front the speedo will only be out by a tiny amount. As these are already out by around 5% it wont make any difference.

 

BMW's Porches etc. have different size rear tyres anyway as standard.

[stef123]

As long as the same size tyre is fitted to each axle it doesn't matter if the front is a different size to the rear. He was probably trying to get you to buy more tyres 

[turbohater]

I cant see the insurance company being very happy if you have an accident with the wrong size tyres fitted

[m1tch]

The 185/65/15s are 8% larger than the stock tyres meaning at 60mph you are actually doing 64 and at 70 you are actually doing 75 - another issue is that as the front and rear are different sizes it could affect the ABS.

I don't think it's technically an MOT failure as each axle had the same sized tyres on, it's just the completely wrong tyre size.

It would seem that the 185/65/15 tyre was fitted to a model of Fiesta so they might have swapped over wheels and tyres or just looked up what tyres the car 'should' have and just bought those.

[George_A_]

Thank you everyone for your replies!!!

I am a bit confused, however...

As in btmaldon's reply, the speedometers are already programmed by the manufacturers to show about 5% higher speeds than the real speed, in order to fit within the law, taking into perspective variables such as the tyre thread, which can affect the speedo recorded speed in the long term...

However, as in m1tch's reply, the tyres fitted on the car were larger (I could clearly see that, there is a big difference with the tyres that have been fitted by the tyres specialist, which definitely seem to have a smaller diameter.)

And then, according to the car expert, http://www.thecarexpert.co.uk/how-accurate-is-a-car-speedometer/, a speedometer should never read a lower speed than the actual car's speed, and this is supposedly the UK law.

So, if 5% is the standard deviation applied to the speedometers by the car manufacturers and, as in the reply by m1tch, the tyre fitted originally on the car was 8% bigger, then, the speedometer would show a 3% lower speed than the one I travelled at.

So, if the article by the car expert is right, these tyres were illegal, if the speedometer was showing me any speed that was lower than my travelling speed.

Is anyone following my reasoning or is it completely wrong?

Thanks again everyone for your input, it is very much appreciated...

Kind Regards,
George

[TomsFocus]

There's a big difference between being legal and passing MOT...

You can have different sized tyres front to back as long as they're the same on each axle as has been said above.

The MOT won't even know which sized tyres your car came with, they'll just check front to rear and side to side.  And they don't test speedometer calibration.  Those tyres would pass MOT no problem at all.

People often fit slightly different sized tyres from original spec due to price or availability.

 

As for being legal, I can't say, speed cameras have to have a tolerance due to speedo inaccuracy so I'm not sure speedos under-reading is even illegal.

[Joss max]

In the old days. The main issue was not tyres size but mixing cross ply tyres with radial tyres. That caused some serious accidents in the day. Thankfully we don't have that issue any more.

[TomsFocus]

4 minutes ago, Joss max said:

In the old days. The main issue was not tyres size but mixing cross ply tyres with radial tyres. That caused some serious accidents in the day. Thankfully we don't have that issue any more.

My Mum was telling me about some tyres she bought a couple of months ago...'they're even radials' she said as if it was the 70s...  

[George_A_]

....so, in other words, my car dealer is right, the tyres were fine for the car, I should try to settle my problem with the "tyre specialist" who sold me at least 2 extra tyres that were not needed, by telling me that I had to change all 4 car tyres to the 195/510X15 size or else I would be driving an illegal car...

The good thing is that I have the attached invoice, where the "tyre specialist" has written down which type of tyres were fitted, with the indication that they were wrong, as well as the type of the tyres he fitted, supposedly the right ones.

I suppose I can take this up with trading standards, as I was mis-sold something I did not need...

Thanks everyone for your input.

[TomsFocus]

He's also fitted the wrong tyres going off that invoice...195/510 would have a ~1 metre tall sidewall.   But we'll ignore his typo lol, they're 195/50.

As I say I don't know the legalities, he may well be right in that they were technically illegal if that speedo law is genuine but I don't believe it is.

However they would pass MOT and don't pose any safety risk so the car dealer is definitely right there.  It may be down to the way the tyre dealer worded it - the fact he put 'incorrect' rather than 'illegal' on the invoice doesn't help, as they were incorrect compared to the original spec.  I'm not sure how you could prove that he said illegal etc. 

[m1tch]

Also quite cheap tyres!

[Bobr]

£33 each inc VAT.   They are probably rubbish.

[isetta]

they might be rubbish but they might do the job, depends on use of car etc. my wife does about 2,000 miles per year around town. recently she cut open a decent make tyre on a sharp curb whilst reversing round a corner. There is no point in spending more for better tyres for her car.

I don't think the MOT place or the garage that sold the car did anything wrong here.

 

[Pullock]

I think the tyres are a personal choice too but personally I wouldn't put cheap or brands I've never heard of on my car, so far the tyres I've used have been around £60-80 each and they feel much different to some cheaper ones I had on an older car.

I had Continental and found then to be very good tyres, now have Michelin on our new car, only done about 70 miles so far so not sure how I feel about them but would expect them to be on par with the Conti's for the price.

At the end of the day your tyres are the only part that touches the road and that's the last thing you want to skimp out on.

[David73]

On 12/15/2016 at 10:51 AM, George_A_ said:

 

So, if 5% is the standard deviation applied to the speedometers by the car manufacturers and, as in the reply by m1tch, the tyre fitted originally on the car was 8% bigger, then, the speedometer would show a 3% lower speed than the one I travelled at.

 

Electronic speedometers are not subject to the statistical variations that mechanical ones used to have. The difference between real and indicated speed is deliberate, not subject to manufacturing.

[isetta]

the speedo might be electronic and not have magnets spinning round inside it like they were in the past, but the electronic signal to the speedo is from a sensor that is affected by how many times the wheels go round. 

If you instal larger tyres (on the front of a fiesta) with 5% more circumference then the car will go 5% faster for the same reading on the speedo, and vice versa. The sensor has no way of knowing the tyres are different to the makers original spec.