Could someone please remind me of the age at which car tyres should be replaced assuming tread wear is otherwise still legal.
I know caravans have to have them replaced after a certain time period.
I have two Dunlops on the back of my quattro which were on the car from new, (M reg) they just don't seem to wear at all!
Does the compound harden? Would this compromise handling? Could this be why I've almost lost the rear end twice this month, whilst cruising gently (30-40mph) around bends.
I took them to a fast fit place recently, who to my surprise said they were ok, I had assumed that they would have jumped at the chance of a double sale.
Or is there another reason for the two rather serene slides. Nothing dramatic, dry conditions, easily corrected, steady throttle...all the more worrying therefore as was behaving myself.
Stu.
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Brill
There don't seem to be any regulations. Most makers reckon spares should be at least 'used with care' after 6 years. That's for tyres which haven't been exposed to UV from sunlight which is the real killer. Atmospheric oxygen is another factor in tyre aging, and aging manifests itself as cracked and hardened tread compound.
I'm surprised your 'in-use' M reg tyres are still OK and I'd be rather cautious. It could be that the loss of grip is a sign of the compound aging and hardening, and I'd have expected to see signs of surface cracking.
You can check tyre ages from the last 3 or 4 digits of the DOT code on the sidewall.
Tyres made in the 1990's have 3 digit code. The first two are the week and the last is the year (eg 458 = week 45, 1998)
Since 2000 it's a 4 digit code, with the year given as as two digits (eg 4501 = week 45, 2001)
Regards
John S
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A 'man in the know' - who owns the local big tyre place - told me that if the tyre is used every day, it will last substantially longer.
(He would not be doing himself any favours by saying so!)
He also said the trend towards 'space saver' spares is because many cars will only have a flat after many years - and the spare has been sitting in the boot all that time, and is unsafe. He claims that 40% of tyre-related accidents (blow-outs etc) are within a week of a 'spare' being put on.
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Ian
I wonder if the daily use keeps them flexible, and it does, by definition wear them out and so limit their age.
As for the blow-outs of spare tyres - I imagine age may be a factor, but I wonder how many are due to being run underinflated, having been rarely checked?
Regards
John S
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The tyres on my ex-army trailer say 1954 and look all right
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I have to travel from Epsom to Dorset and back tomorrow, A303 I guess, which passes Micheldever Tyres...think I'll pop in and get them changed.
Stu.
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I am mystified by tyre life. My Triumph stood outside for ten years before I decided to restore it and it has since put on another six years (two years restoration and over four years use), all on the same set of tyres. The tyres weren't even new at the start of all that and yet they still show absolutely no signs of deterioration.
I took the car to a respected tyre depot earlier this year and asked their opinion on the condition and safety of the tyres. After a through checking, including removing one of them from the wheel, they said the tyres were as sound as new and though *in theory* I should replace them they could see no good reason to do so. The tyres are Goodyear Grand Prix S, size 185x14 (radial ply).
Now to the other extreme. My BMW was less than eight years old when I bought it but the spare was in a terrible state. It had cracks between the treads that were so wide and deep you could see the carcass. That was a different make to those on the Triumph but that may have had nothing to do with the difference in life so I won't mention the maker's name.
All I can think of is that modern rubber compounds age quicker than the old ones.
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Dizzy
Yes, huge variation. My Minor sat in the garage for 10 yrs during restoration, on tyres already a few years old. The tyres looked OK but after 100 or so miles two of them were showing cracks indicating the treads were about to separate. So, they were scrapped.
My trailer tyres, litle used, look fine despite being 20 years old!
Odd with the BMW tyre as it didn't see UV. My previous BMW had a spare 6 years old which had never been on the road, but looked as it would on a new car.
Regards
John S
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In response to Stu's original message. There are no regulations that I've heard of.
The point about regularly used tyres lasting longer is true and I did hear once that when the surface of the tyre starts cracking or 'crazing', then it is time for a change (usually 4-6 years.
Also a tyre that is more than 6 years whether used or unused should be scrapped, as the compounds deteriorate with age.
Let's remember that these tyres keep you safely on the road so let's err on the side of caution for safety's sake.
Regards - Jon S.
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Sorry, John, I should have said that the BMW spare had obviously been run on the car at some time as it was more than half worn.
I bought the car from a non-franchise dealer and he was clearly embarrassed when I showed him the tyre, though he would only agree to replacing it with a bought-in 'part-worn' of unknown history, which I wasn't very happy about.
I can't believe that the tyre was cracked when it was put away and it wasn't many months since the car had had its last BMW service so any cracking should have been picked up then.
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It's not just the rubber compound that can give out with age. Three rear tyres on our BX estate two at once, another later (it just does not wear the treads!)have had the inner construction fail leading to bulges in the tread and rapid appearance by the steel plies.
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The recommendation for caravan tyres to be replaced is based on the premise that the tyres spend long periods without moving. While restoration projects could be regarded the same as caravans, cars used regularly have no recommended replacement life that I am aware of. The actual recommendations for caravans are ideally 5 years, but 7 years in any case. I would suggest that inspection, off the wheel, at a reputable tyre dealer is infinitely better than any broad-brush recommendation.
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Dizzy
Second-hand tyres present an interesting conundrum. Every year millions of second-hand tyres change hands attached to second-hand cars. They change hands with often just a cursory inspection, no real evidence of history and no opportunity to inspect the internals.
On that basis buying a used tyre off the rim does give the opportunity for a better inspection, both internal and external. Yes, the risk is it's crash salvage, but this could well have left little or no damage. On that basis the off the rim tyre, with the opportunity for inspection arguably presents the lower risk.
The second hand car you're inspecting could be running on a set of recently purchased second-hand tyres!
Regards
John S
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Micheldever Tyres today:
2 x 205/60R15 Michelin Pilot Primacy 91V @ £54.00
Courteous and very efficient service ... what a difference!
Thanks to HJ for the recommendation, and to posts here of course.
Stu.
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