Two things about tyres almost nobody checks until something forces them to: how old they are, and where they came from. Tread depth gets looked at, because that is what the MOT talks about and what a twenty pence piece measures. Age and provenance get ignored.
Both of them can matter more than the tread does.
Reading the date on a tyre
Every tyre has its manufacturing date moulded into the sidewall, as the last four digits of the DOT code. The first two are the week, the last two are the year. 2523 is the twenty-fifth week of 2023. 0819 is early 2019.
Two things to know. The full code is often moulded on one side of the tyre only, so if you cannot see it, look at the inner face. And a three-digit code means the tyre was made before 2000, which on a car in daily use is a finding rather than a curiosity.
It takes about a minute to check all five. Most people have never done it once.
Why age matters when the tread looks fine
Rubber is not inert. It hardens with time, and the compounds that keep it flexible migrate out of it whether the tyre is being used or not. An old tyre grips less in the wet and cold even with plenty of tread, and it becomes more prone to cracking.
You can often see it. Fine cracks in the tread grooves or a crazed pattern in the sidewall — perishing — is age showing. So is a hard, shiny look to rubber that ought to be matt.
This is exactly why a low-mileage car can be on dangerous tyres. A vehicle that does three thousand miles a year keeps its tread for a decade and quietly ages its tyres out from underneath itself, which is one of the things covered in our guide to cars that have stood for months. Standing still is not kind to tyres, particularly on one flat spot for a winter.
What the law actually says about age
For cars: nothing. There is no legal maximum age for a tyre on a car in the UK.
For larger vehicles there is. Since regulations that came into force in 2021, tyres aged over ten years cannot be used on the front steering axles of goods vehicles over 3.5 tonnes, buses, coaches and minibuses, nor on the rear axles of minibuses that do not have twin wheels. The date marking must be legible, and using a tyre whose markings have been damaged or defaced is itself an offence. Retreads count from the retreading date.
That rule tells you something even if you drive a car. The government drew a line at ten years for the vehicles it regulates most closely, and most tyre manufacturers recommend the same figure for everyone else. Ten years is not a cliff edge, but a tyre approaching it deserves inspecting rather than assuming.
Tread depth, properly
The legal minimum is 1.6mm across the central three quarters of the tread, around the entire circumference. Not in one spot — all the way round, and across that whole central band.
Below it the tyre is illegal, and the penalty is up to £2,500 and three penalty points for each tyre. Four bald tyres is not one offence.
The practical advice from the trade is to replace at around 3mm, because wet braking distances lengthen considerably between 3mm and the legal limit. Our guide to tyres and tyre services covers what a fitter is actually looking at, and our MOT guide covers how it is assessed at test time.
Part-worn tyres and the rules that govern them
Selling part-worn tyres is legal. Selling them the way a lot of places do is not.
The Motor Vehicle Tyres (Safety) Regulations 1994 set out what a part-worn tyre must satisfy before it can be sold. Among the requirements:
It must be permanently and legibly marked PART-WORN, in uppercase letters at least 4mm high — and that marking must not be hot branded or cut into the tyre.
It must have at least 2mm of tread across the full breadth and around the entire circumference. Note that this is more than the 1.6mm legal minimum for a tyre in use, and it applies to the full breadth, not the central three quarters.
It must be free of lumps, bulges and tears, with no exposed ply or cord, and no unrepaired penetration damage. Cuts must not exceed 25mm or 10% of the section width, whichever is greater, where they reach the cord or ply.
The original speed and load markings must still be legible, and the tyre must have passed an inflation test before sale.
Investigations by tyre safety organisations have repeatedly found that a large proportion of part-worn tyres offered for sale failed to meet these requirements — most commonly the marking, but also the condition standards. If you are buying part-worn, look for the PART-WORN marking and the date code before anything else. A seller who cannot show you either is telling you what kind of operation it is.
The arithmetic nobody does
A part-worn sold at the legal minimum of 2mm has 0.4mm of legal life left. A new budget tyre might start at 8mm. Divide the price by the usable tread and the part-worn is very often the more expensive tyre, on a casing whose history — kerb strikes, under-inflation, previous repairs — you know nothing about.
There are situations where a good part-worn makes sense: a car that is being sold shortly, an unusual size, a temporary fix. As a routine way of buying tyres it usually is not the saving it looks like.
Where it is worth calling us: when a tyre has already failed rather than just worn out — a blowout, a sidewall split, a puncture with no usable spare, or a locking wheel nut key that has gone missing. The car goes on a flatbed to a fitter rather than being driven on a damaged tyre. We cover Sheffield and South Yorkshire at any hour — call DK’s Recovery on +44 7867 860723. Our guides to blowouts and when a flat tyre needs recovery cover the decision at the roadside.
A five minute check, once a season
Pressures, cold, against the figures on the door pillar. Tread depth in three places across each tyre, not just the outer edge — uneven wear across the width points at alignment or pressure problems, not at the tyre. The date code on all five. Sidewalls for cracking, bulges and kerb damage. And the spare, which is the one that gets forgotten and the one you will need in the dark.
Uneven wear is worth acting on rather than noting. It means something else on the car is wrong, and a new tyre fitted to an unresolved alignment problem wears out the same way, just later. Our guide to driving on a puncture covers the other end of the same subject — what a damaged tyre does if you keep going on it.
Frequently asked questions
Where do I find the age of a tyre?
On the sidewall, in the DOT code. The last four digits are the date: the first two are the week of the year, the last two are the year. So 2523 means the twenty-fifth week of 2023. The full code is often only moulded on one side of the tyre, so if you cannot find it, look at the inner face.
Is there a legal age limit for car tyres?
No. There is no maximum age for tyres on a car in the UK. Since 2021 tyres aged over ten years have been banned from the front steering axles of goods vehicles over 3.5 tonnes, buses, coaches and minibuses, and from the rear axles of minibuses without twin wheels, but that rule does not apply to cars. Many manufacturers still recommend replacing tyres at around ten years regardless of tread.
Is it legal to sell part-worn tyres?
Yes, but only under strict conditions set out in the Motor Vehicle Tyres (Safety) Regulations 1994. Among other things the tyre must be permanently and legibly marked PART-WORN in uppercase letters at least 4mm high, must have at least 2mm of tread across its full breadth and entire circumference, must be free of exposed cord, lumps, bulges and unrepaired penetration damage, and must have passed an inflation test.
What is the legal minimum tread depth?
1.6mm, across the central three quarters of the tread and around the entire circumference. Below that the tyre is illegal, and you can be fined up to £2,500 and given three penalty points for each one. Most tyre fitters advise replacing at around 3mm, because wet braking performance falls off well before the legal limit.
Are part-worn tyres a false economy?
Often. You are buying an unknown amount of remaining life — a part-worn sold at the legal minimum of 2mm has very little usable tread left before it reaches 1.6mm. Measured by cost per millimetre of usable tread, a budget new tyre frequently works out cheaper, and it comes with a known history.
Does the spare wheel need checking too?
Yes, and it is the tyre nobody looks at. A space saver that has sat under the boot floor for eight years can be badly under-inflated or perished, and you will find out at the exact moment you need it. Check its pressure and its date code when you check the others.
