Safe Speed Forums

I needed an emergency tyre replacement yesterday following a puncture. My car takes 195/65 91H tyres. However, I didn't notice till this morning and after driving 60 miles that the tyre they fitted is actually 195/60 88H.... The car seemed fine, with most of the journey being at motorway speed. However, I'm not that mechanically-minded so could someone tell me what the potential implications/problems could be with this - it's the front offside tyre, the other three being 195/65 91. (All tyres/wheel rims are 15" if that's relevant)

Cheers

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Why can't we just use Common Sense?

one problem could be to wear your diff out as it's constantly turning trying to allow one wheel to turn quicker than the other (assuming the car's front wheel drive).
could also affect steering (it should try and pull to one side), braking, as the brakes will have different masses to slow down and suspension as again, each side is working with different masses also not with the mass the manufacturer designed it for.
Should be OK short term, I had to do similar with a 4x4 for about 100 miles with no long term problem. but you really, really need to get them matched ASAP.

PS the police will probably have a word if they catch you too.

What IS the 88 or 91 parameter?

I'm used to

195 / 60 VR 15

where:

* 195 is the tread width
* 60 is the aspect ratio of tread to sidewall
* VR is the speed rating
* 15 is the wheel size

So far I haven't guessed at the mystery parameter.

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Paul Smith
Our scrap speed cameras petition got over 28,000 sigs
The Safe Speed campaign demands a return to intelligent road safety

Tyre sizes are made up of a number of different numbers and letters. For example tyre size 175/70 R 13 82 T is made up of the following information:

175 The tyre section width in millimetres (That is the width of the tyre tread)
70 The aspect ratio in % (the height of the sidewall divided by the tyre's width)
R Denotes the tyre's construction type - in this case it's a radial
13 Rim diameter in inches
82 Load Index
T Speed Rating

It's the load and speed rating.

91H = 615kg max speed 130mph
88 = 560kg

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It's tricky doing nothing - you never know when you're finished

Cheers for the quick replies......

Full specs are:

195/65 R15 91H for the older three
195/60 R15 88H for the new replacement

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Why can't we just use Common Sense?

Of course it is. I knew that. I was confused by the lack of a wheel size, your honour. It won't happen again.

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Paul Smith
Our scrap speed cameras petition got over 28,000 sigs
The Safe Speed campaign demands a return to intelligent road safety

I would take it back and ask them to change it for the correct one, and it should be done without extra charge. The car won't pass its MOT with mismatched tyres on the same axle, so the job they have done is not of satisfactory quality.

Well I'm convinced now! It's going back tomorrow. Hope it'll be OK for another 100 miles.

I do find this a bit worrying though - only noticed on a casual glance this morning. I know I should have checked when collecting the car but you do tend to assume the tyre being put on will be the same as the one being removed . And I'm sure there are many car owners out there who wouldn't realise there was a problem that needed sorting, even if the specs were written out in front of them.

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Why can't we just use Common Sense?

Not that its of any help now, but I always check what a tyre fitter's put on my vehicles after one cowboy changed my caravan tyres and charged me for valves and balancing. It was only when I got home that I realised they'd left the original inner tubes in place and hadn't fitted valves at all.

Naturally, they were full of apologies (claiming it was an easy mistake to make ) and refitted the tyres properly, removing the inner tubes and fitting valves as originally requested.

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Will

Traction control/ABS and the latest clever auto gearboxes can get confused by even slight differences in rolling diameter.

At the garage where my brother works a customer brought a car in that had a new gearbox under warranty at another dealer and it still kept hunting between gears and getting stuck in gears. When the mechanic took the wheels off he noticed that the tyres were mis-matched. A new set of (matching!) tyres fixed the gearbox problem.

The difference is 0.8 inch in diameter and 2.4 inch circumference.

Do you have the car's handbook? It will specify the tyre size, speed capability and load rating required. Is there a possibility that the other three tyres are incorrect? Depending on the age of the car, I guess someone might have fitted them instead of OE. Assuming it IS the new tyre that's different, I'd insist on a change and if they give you any hassle at all, I'd be very quick to threaten with Trading Standards. If you had an accident like that, the tyres would be one of the first things the insurance assessor would look at and if it's a big claim, it could be just the excuse they need to try and wriggle out.

No, the car definitely takes 195/65 91H - handbook states this and on the inside of the driver's door, (and I've gone through about 4-5 sets of tyres in under 2 years )

Anyway I took it back last night, got it instantly replaced for the correct (and more expensive) tyre at no extra cost , along with plenty of apologies.

Thanks for all the advice

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Why can't we just use Common Sense?

Here's a good site for this sort of thing....

http://www.tyresave.co.uk/contents.html

Check the "Tyres" index for speed ratings, sizes, loadings etc...

Got stung like that on cheap tyres on an old car years ago - fitted 185 instead of 195. Only found out when i got a puncture and tyre damaged beyond repair.
Now - i like to see what's coming off, where it's going and how much tread's on it / method of tightening nuts/torque.Also gives me a chance to check up on disks .Last change -found dealer maintained car had loose (dropped out when wheel removed) rear drum screw.Trouble is that a lot of the big places are upset --worried about Health and safety, so they insist you stay in waiting area.

blimey, i walked, well drove, out of a well known tyre fitter franchise cos he wanted to fit a GT pattern tyre when all the others were M+S, evan after I pointed out the difference he was quite insistent.... must have had one out back

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Fear is a weapon of mass distraction

Thanks for the site link. Very useful info.

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"Experience isn't everything - but it's most of it".

Just because you're paranoid doesn't mean they're not out to get you.