Part-worn tyres: the UK rules, and why we do not fit them
8 min readBy Wheel Fit
The short answer: selling part-worn tyres is legal, but they must have at least 2mm of tread across the full breadth, be free of specific damage, and be permanently marked PART-WORN in letters at least 4mm high. Trading Standards surveys repeatedly find most on sale fail these tests.
What the law requires
Under the Motor Vehicle Tyres (Safety) Regulations 1994, a part-worn tyre may only be supplied if it:
- has original tread of at least 2mm across the full breadth and around the entire circumference;
- is free from any cut, bulge, lump or tear exposing the cords;
- has not suffered internal or external separation of the structure;
- is permanently and legibly marked PART-WORN in uppercase letters at least 4mm high — and that marking must not be made by hot branding or cutting into the tyre.
Failing to comply is an offence carrying a fine and up to two years' imprisonment.
The problem in practice
Local authority Trading Standards teams test part-worn tyres regularly, and the results are consistently poor — investigations have found the overwhelming majority of tyres sampled were not correctly marked and therefore non-compliant, with some carrying dangerous defects.
The deeper problem is that a used tyre's history is unknowable. You cannot see whether it has been run flat, kerbed hard, repaired badly, or stored outside for five years. All of those cause damage that is invisible from the outside and only found by inspecting the inner liner off the rim.
The arithmetic
A new tyre starts with around 8mm of usable tread and is legally finished at 1.6mm — call it 6.4mm of life.
A part-worn sold at the legal minimum of 2mm has 0.4mm before it is illegal. Even a generous 4mm part-worn gives you around 2.4mm, roughly a third of a new tyre's life. Priced against a budget new tyre, part-worns are frequently poor value per mile as well as an unknown quantity.
If you are going to buy them anyway
- Check for the PART-WORN marking. If it is not there, the sale is illegal — walk away.
- Measure the tread yourself, in several places across the width.
- Check the DOT date code. A tyre with 5mm of tread and a 2011 date is old rubber.
- Inspect both sidewalls for cracking, bulges and repair patches.
Our position
We do not fit part-worn tyres. Not on principle about the law — it is that we cannot inspect a used tyre's history well enough to put our name to it, and a budget new tyre from a known brand costs little more and comes with its full life ahead of it.
What you cannot find out about a used tyre
The legal checks cover what a tyre looks like now. They cannot tell you what it has been through, and that is the part that matters:
- Whether it has been run flat, which destroys the inner liner while leaving the outside looking fine — can you drive with a puncture?
- Whether it has been kerbed hard enough to break internal cords without a visible bulge yet.
- How it was stored — heat, sunlight and ozone all age rubber — storing tyres properly.
- Why it was taken off a car in the first place.
- Its repair history, and whether any repair met the standard — can a puncture be repaired?
A part-worn also arrives with no tyre label, so you lose the one directly comparable measure of wet grip you would get on any new tyre — the tyre label explained.
Common questions
- Are part-worn tyres illegal?
- No — selling them is legal, provided the Regulations are met. The problem is how often they are not, and how little you can verify.
- What if the tyre has no PART-WORN marking?
- Then the sale does not comply. It is worth reporting to Trading Standards, and it is certainly worth walking away from.
- Are ex-demo or nearly-new tyres the same thing?
- A tyre that has genuinely covered very few miles is a better proposition, but you still cannot verify its history — and it is still a part-worn in law, so the marking rules apply.
- Is a budget new tyre really not much dearer?
- Usually not, once you compare full life rather than sticker price — see what new tyres cost and budget vs premium tyres.
Sources
If cost is the concern, tell us. There is a real spread across the budget end of the market and we would rather find you a sensible new tyre than fit something we are unsure about. Call 07989 606060.
