Tyres are your car's only contact with the road, yet they're one of the most neglected safety components. Worn or damaged tyres significantly increase stopping distances and the risk of a blowout, especially in wet conditions.
Legal Requirements
The legal minimum tread depth in the UK is 1.6mm across the central three-quarters of the tyre's width, around its entire circumference. Driving with illegal tyres can result in:
- A fine of up to £2,500 per tyre
- 3 penalty points per tyre
- If all four tyres are illegal: £10,000 in fines and 12 points (automatic disqualification)
When to Replace: 3mm, Not 1.6mm
While 1.6mm is the legal minimum, tyre and safety experts recommend replacing tyres at 3mm. Testing by MIRA found that the difference in wet braking distance between 3mm and 1.6mm can be as much as 44%. At 1.6mm, your stopping distance in the wet could be 10 metres longer than at 3mm — that's roughly two car lengths.
The 20p Test
The quickest way to check your tread is the 20p test. Insert a 20p coin into the main tread grooves. If you can see the outer band of the coin, your tread is below 1.6mm and the tyre needs replacing. Check at several points around each tyre, as wear can be uneven.
Tyre Pressure
Under-inflated tyres are dangerous and expensive:
- They overheat and can blow out at motorway speeds.
- Driving with tyres just 20% under-inflated increases fuel consumption by 10%.
- They cause uneven wear, meaning you'll need to replace them sooner.
Check your tyre pressures at least once a month and before any long journey. The correct pressures for your car are usually on a sticker inside the driver's door or fuel filler cap, or in the owner's manual.
Find Your Correct Tyre Size
Not sure what tyres your car needs? Use our free tyre check to find the manufacturer's recommended tyre sizes, pressures, speed ratings and rim specifications for your exact vehicle.