You are looking at a tyre with a web of fine cracks running across the sidewall. The tread is fine, maybe 4 or 5mm still left. The car drives fine. But those cracks looked smaller a year ago.
So is this dangerous, or is it just cosmetic? Here is the part most drivers never get told. Tread depth tells you nothing about age safety. A tyre with 5mm of tread can still be at the end of its safe life, and when an aged tyre finally fails, it usually fails at speed.
We read these date codes all week, on driveways from Glasgow to the Highlands, and the same surprise comes up again and again. People check their tread religiously and never once look at how old the rubber actually is. This guide fixes that. Here is how to read your tyre’s real age in 60 seconds, what the cracks mean, and when replacement is genuinely needed.
Quick answer: Find the DOT code on the sidewall and read the last 4 digits. The first 2 are the week, the last 2 are the year. Under 5 years is usually fine. From 5 to 10 years, inspect annually. At 10 years or older, replace regardless of tread.
Read Your Tyre’s Age in 60 Seconds
This is the single most useful thing you can learn about your tyres, and it takes less than a minute with your phone torch.
Find the DOT code
Look on the sidewall, the flat side of the tyre, not the tread. You are searching for the letters DOT followed by a string of characters.
At the very end of that string sits a 4-digit number. That is your date code. One quick note from experience: the date code often appears on only one side of the tyre, so if you cannot find it, check the inner face too.
Read the 4 digits
The format is simple once you know it.
- First 2 digits = the week of the year (01 to 52)
- Last 2 digits = the year of manufacture
So 4718 means week 47 of 2018, roughly mid-November 2018. 0321 means week 3 of 2021, around mid-January 2021. That is the whole trick.
If you only see 3 digits
A 3-digit code means the tyre was made before the year 2000. That makes it at least 25 years old.
Replace it without hesitation, whatever the tread looks like. We mostly see these on classic cars and on spares that have been forgotten in the boot for decades.
Check all four, and the spare
Tyres often get replaced in pairs or one at a time, so your four can easily be different ages.
Your spare is almost always older than the four on the road, so do not skip it. Photograph each DOT code with your phone so you have a record to compare over time.
What to Do in the Next 60 Seconds
If you have just noticed cracks or you are about to book an MOT, run this quick check.
- Find the DOT code on each tyre and the spare.
- Photograph each one with your phone.
- Work out the age. Last 2 digits are the year, first 2 are the week.
- Photograph any cracks so you can track them over time.
- Compare against the rules below. Under 5 years usually fine, 5 to 10 inspect yearly, 10+ replace regardless of tread.
- Call us on 07955 533000 if you want a Scotland-wide driveway inspection, or WhatsApp the DOT-code photos and we will give you an honest read.
No pressure, no obligation. Sometimes the honest answer is that your tyres are aged but perfectly fine for now, and we will tell you that just as readily.
The UK Age Rules: What Actually Applies
There is a lot of confusion here, so let us be precise. This is where a lot of online advice gets it wrong.
There is no general legal age limit for car tyres
For ordinary cars and vans, UK law does not set a tyre age limit.
What the law does require is a minimum tread depth of 1.6mm across the central three-quarters around the full circumference, plus sound condition with no cuts, bulges, or exposed cords. A 12-year-old tyre with perfect tread and no visible damage is technically legal. Legal, though, is not the same as safe.
Where 10-year-old tyres ARE a legal fail
Since February 2021, tyres aged 10 years or older cannot be fitted to the front axles of HGVs over 3.5 tonnes, buses, and coaches. For minibuses, the 10-year limit applies to all axles, not just the front.
Those vehicles fail their MOT with a 10+ year tyre in those positions. Here is why it matters for your car. The government effectively accepts that 10-plus years is unsafe for professional drivers carrying passengers. The same physics applies to the rubber on your family car.
What causes an MOT failure at any age
- An illegible or missing date code on the sidewall
- Cuts, cracks, or bulges that expose the cords
- Tread depth below 1.6mm
- Age-related cracking deep enough to compromise the internal structure
- Sidewall cracking that exposes cords, which is an automatic fail
When Manufacturers Actually Recommend Replacement
Here is something most articles hide: the experts do not fully agree. Rather than pretend there is one tidy answer, here is the honest spread.
| Source | Recommendation | Notes |
| BTMA (British Tyre Manufacturers’ Association) | Annual professional inspection from year 5, replace by 10 | UK industry-standard source |
| Michelin | Inspect annually from year 5, replace by 10 years | One of the more conservative voices |
| Continental | Inspect annually from year 6, replace if showing aging signs | Major original-equipment maker |
| Goodyear | Inspect from year 5, replace by 10 regardless of tread | Aligned with BTMA |
| German BRV “5-year rule” | Inspect annually from year 5 | European industry baseline |
| UK MOT rules (Feb 2021) | 10+ years fails on HGV, bus, coach, minibus axles | Legal limit for commercial vehicles |
| Caravan and trailer makers | Replace by 6 years even with good tread | Storage degradation speeds aging |
The honest takeaway is this. Almost everyone agrees on a 5-year inspection rule and a 10-year replacement ceiling. The 6-year figure comes from specific manufacturer guidance and is widely respected. There is no single correct number. But once your tyres pass 10 years, the industry consensus is clear: replacement is best practice.
We could push every driver with 5-year-old tyres to replace today. We don’t. We would rather give you the facts and let you decide.
Dangerous Cracks vs Harmless Cracks
Not every crack means panic, and not every crack is cosmetic. After reading thousands of these, here is how we actually judge them.
| What you see | What it means | What to do |
| Very fine web-like crazing in the sidewall | Early UV and ozone aging, rubber starting to harden | Monitor monthly, replace within 12 to 18 months if it spreads |
| Deep cracks you can fit a fingernail into | Significant aging, integrity compromised | Replace within 30 days, avoid long high-speed trips |
| Cracks at the base of the tread grooves | Tread block separation risk, particularly dangerous | Replace promptly, blocks can shed at speed |
| Cracks at the shoulder (tread-to-sidewall corner) | A high-stress zone, riskier than elsewhere | Replace promptly |
| Any crack exposing internal cords or canvas | End of safe life, MOT auto-fail | Replace immediately, do not drive at speed |
| Bulge or lump in the sidewall | Internal structural damage, not just aging | Stop driving, replace immediately |
| Flat-spot deformation after months unused | Compound has set out of round | Inspect, may ease after driving, may not, ask a fitter |
| Fading or discolouration without cracks | UV exposure, no structural problem yet | Monitor, inspect annually |
If you spot a bulge rather than a crack, that is a different and more urgent problem. Our guide on a bulge in your tyre covers why that one means stop driving now.
Why Tyres Age Even When They Are Not Used
This is the bit that catches people out. A tyre does not need miles to wear out. It just needs time, weather, and stillness.
UV light
Sunlight slowly breaks down the rubber compound. Cars parked outside age faster than garaged ones, and south-facing spots that catch the afternoon sun are the worst of all. In Scotland, Highland summers with their long daylight hours and the many Glasgow estates without garages are where we see the most UV damage.
Ozone
Ozone in the air attacks rubber from the surface inward. It is worse in busy urban settings, so the Glasgow city centre, the M8 corridor, and central Edinburgh all push more ozone at your tyres than a quiet rural road.
Heat cycling
Every time you drive, the tyre warms and expands, then cools and contracts when parked. Repeated over years, that cycle gradually breaks down the internal structure. Driven tyres age this way, while parked tyres develop a different problem entirely.
Lack of use
Here is the counter-intuitive part. Tyres need to flex to keep their internal oils and conditioners moving through the rubber. A tyre that sits still dries out, stiffens, and cracks. A classic car doing 500 miles a year often has older-feeling rubber than a commuter doing 12,000.
Scotland-specific factors
A few things make Scottish tyres age faster than the UK average:
- Winter road salt between November and March is corrosive to rubber compounds.
- Freeze-thaw cycles put driveway-parked tyres through dozens of expansions and contractions each winter.
- Highland summer UV and coastal salt air along the Ayrshire coast and west-coast ferry routes add to the load.
The damp itself is not really the enemy. It is the freeze-thaw and UV cycle on top of the salt that does the damage.
Where Aged Tyres Are the Highest Risk
Some vehicles age their tyres invisibly, because low mileage hides the problem. These are the ones we worry about most.
Classic cars
Sunday drivers rack up age without wear. Even when garaged, the rubber still crazes, and the tyres may date back to whenever the restoration was done, sometimes 15 years or more. The rubber does not care about sentimental value.
Second and weekend cars
Low annual mileage masks aging completely. The owner sees healthy tread and assumes the tyre is fine. This is common in Scottish households with one commuter car and one family car driven once a fortnight, right across the Glasgow and Edinburgh suburbs.
SORN-then-reactivated cars
A car sitting on a Statutory Off Road Notification for a year or more has tyres that never flex. The rubber stiffens and the sidewalls crack. When the car comes back, the owner sorts the MOT and rarely thinks to check the tyre dates. Inherited cars and lockdown-era second cars returning to the road are classic cases.
Caravans, trailers, and motorhomes
These often sit for nine months a year, frequently outdoors where UV and freeze-thaw concentrate. Industry guidance is to replace at 6 years regardless of tread. Scotland’s touring season from May to September then loads a heavy summer onto tyres that have sat all winter.
Spare wheels: the forgotten tyre in your boot
Your spare is often older than the four on the road. It avoids UV in the boot, but it still suffers heat cycling and the stiffening that comes from never being used.
The dangerous assumption is “it has never been used, so it must be fine.” In reality, a 10-year-old spare is no safer than a 10-year-old road tyre, and you only find out at the worst moment. If you are not sure you even have a usable spare, our guide on no spare wheel and a flat is worth a read.
Used cars on the forecourt
Dealers sometimes leave original 6-plus year tyres on a car that otherwise looks spotless. Always read the DOT code on all four, plus the spare, during your inspection. If any tyre is 6 years or older, use it to negotiate a replacement into the deal.
Pre-MOT: A 5-Minute Age Check
Catching an aged tyre before the test means you schedule a replacement on your terms, instead of failing and paying for a re-test.
Why it matters: MOT testers check tyre age and condition. Cracking that exposes cords is an automatic fail, and an illegible date code fails too.
Run this quick check at home:
- Read the DOT code on each tyre and the spare, and photograph each.
- Check tread depth. The 20p test works: insert a 20p coin into the main groove, and if the outer band is visible, you are at or below 3mm.
- Inspect the sidewalls for cracks, bulges, and cuts.
- Look into the tread grooves for cracking at the base.
- Check the shoulder where the tread meets the sidewall.
- If any tyre is 8+ years old and showing visible cracks, book a replacement before the MOT.
- If any tyre is 10+ years old, replace it regardless of how it looks. That is industry best practice.
When Mobile Fitting Wins for Age-Related Replacement
For aged tyres, the mobile model has some genuine advantages over a garage trip.
- Same standard fitting at your driveway, including matching your existing brand and model where we can.
- Pre-MOT replacement on your schedule, so you never drive to a garage on tyres you already suspect.
- Matching pairs or full sets brought to you in a single visit.
- Spare wheel replacement at home, so you sort the forgotten one without ever needing to use it on the road.
- A no-pressure driveway inspection. We read your DOT codes and crack patterns and give you the straight answer.
- Honest scope. If your tyres are aged but legal and showing no concerning cracks, we will say so and leave them be.
That last point is the whole ethos. We do not guess, we diagnose, and we are happy to tell you when you do not need to spend.
How Much Does Replacement Cost?
We always quote for your exact tyre size, but here is the realistic UK picture so you can plan.
| Scenario | Typical UK cost | Notes |
| Single tyre (budget, basic sizes) | £60 to £100 | Includes fitting and balancing |
| Single tyre (mainstream brand) | £80 to £160 | Most UK family cars |
| Single tyre (premium / performance) | £140 to £300+ | Run-flat, EV, large diameter |
| Pair (same axle) | £160 to £440 | Sensible if the partner tyre is also 6+ years |
| Full set of four (mainstream) | £320 to £640 | Often best value for an aged set |
| Full set of four (premium) | £560 to £880+ | Performance, EV, large premium |
| Spare wheel replacement | £60 to £200 | Match the road tyres |
| Caravan / trailer pair | £80 to £200 | Often LT-rated, similar to a van |
One practical tip from the driveway: if money is tight, you do not always have to do all four at once. A common approach is to replace the worst axle first and schedule the second pair a few months later. Mobile prices sit very close to garage prices, so always ask for your exact size before booking.
Tyre Storage: How to Make Replacements Last
If you swap seasonally or keep a spare set, good storage genuinely buys you years.
For stored tyres:
- Keep them somewhere cool, dry, and dark, ideally indoors.
- Store them off the ground on shelves or pallets, since bare concrete leaches moisture.
- Keep them out of direct sunlight and away from ozone-makers like electric motors and welders.
- Stand them upright, or stack them flat and rotate the stack every four weeks to avoid flat-spotting.
For the spare in your boot:
- Keep it at the recommended pressure, often around 60 PSI for a space saver.
- Check that pressure every 6 months.
- Inspect it for cracking at every annual service.
- Replace it at 6 years regardless of use.
A Pattern We See Across Scotland
Here is a scenario that lands on our schedule almost every week, especially in the run-up to MOT season.
A driver gets in touch about a low-mileage second car, maybe 10,000 miles total across 8 years. The tread is still healthy at around 4mm, so on paper the tyres look fine. But the sidewalls have started to show that fine web of crazing, and the owner is unsure whether it is serious.
We read the DOT codes and confirm what the cracks already suggest: the tyres are 8 years old, and the crazing pattern means the rubber compound is past its useful life. The BTMA inspection rule applies, and with an MOT coming up, replacement is the sensible call.
What we usually do is match the original brand and model where possible, then replace the worst axle first as a cost-staging option. The driver schedules the second pair a few months on, keeps the older spare on the list to sort next, and goes through the MOT without any roadside drama waiting down the line.
That is the quiet value of checking age early. No crisis, no breakdown, just a planned swap on your own terms.
Frequently Asked Questions
How can I tell how old my tyre is?
Look on the sidewall for the letters DOT followed by a string ending in a 4-digit number. The first 2 digits are the week of the year, the last 2 are the year. For example, 4718 means week 47 of 2018. The date code may appear on only one side of the tyre.
Is there a legal age limit for car tyres in the UK?
For ordinary cars and vans, no. UK law sets no age limit. For HGVs, buses, coaches, and minibuses, tyres aged 10 years or older became illegal on the front axles (and all axles on minibuses) in February 2021. For cars, 10 years is the practical limit under industry best practice.
Do tyres expire even if they are not used?
Yes. Rubber degrades over time regardless of mileage. UV, ozone, heat cycling, and lack of flex all break down the compound. A 10-year-old tyre with full tread can be less safe than a 5-year-old tyre with half the tread. Classic cars, second cars, and stored spares are most at risk.
Are cracks in tyres an MOT failure?
Fine surface crazing on its own is not usually a fail. Deep cracks that expose internal cords or canvas are an automatic MOT failure. Sidewall cracks deep enough to compromise the structure will also fail. The tester’s judgement applies.
How long do tyres last?
By mileage, typically 20,000 to 40,000 miles depending on brand, driving style, and conditions. By age, industry best practice is annual inspection from year 5 and replacement by year 10 regardless of tread. Caravan and trailer tyres should be replaced at 6 years.
Should I replace tyres after 6 years?
Not automatically, but you should inspect them annually from year 5. Some manufacturers recommend replacement at 6 years, while others accept up to 10 years if there are no signs of aging. High age combined with visible cracking is when replacement becomes urgent.
Is it safe to drive on tyres with cracks?
It depends on the cracks. Fine surface crazing is a monitoring point, not an immediate danger. Deep cracks a fingernail fits into, cracks at the shoulder, cracks in the tread grooves, or any crack exposing cords mean replace immediately. When unsure, get a professional inspection.
How long do tyres last in storage?
Properly stored tyres, kept cool, dry, dark, off the ground, and out of UV, can last 6 to 10 years before fitting. Once a tyre is fitted, the in-service clock starts. A spare in the boot ages much like a fitted tyre, even if it is never used.
Worried About Your Tyre Age? Here Is What to Do
You do not need to guess, and you almost certainly do not need to panic.
- Read the DOT codes on all four tyres and the spare.
- Photograph any cracks so you can track them over time.
- WhatsApp the DOT codes and crack photos to us for an honest assessment: replace, monitor, or fine for now.
- Book a driveway inspection or replacement across Scotland, with 30 to 45 minute urban arrival and honest Highland times.
- Call 07955 533000. Scotland-wide, 24/7.
We cover Glasgow, Edinburgh, Aberdeen, Dundee, Inverness, and the Highlands. Aged but legal? We will tell you. Genuinely past it? We will bring the right tyres to your door. Either way, you get the straight answer.
