Two routine checks — tread depth and pressure — contribute more to road safety than almost any other maintenance task, and each takes only minutes. The following explains the method and the legal position in the UK.
The legal requirement
Car tyres must maintain a tread depth of at least 1.6mm across the central three-quarters of the tyre, around its entire circumference. Falling below this is an offence, carrying a fine of up to £2,500 per tyre and three penalty points each. Industry guidance recommends replacement at 3mm, well in advance of the legal minimum.
The 20p test
Insert a 20p coin into the principal tread grooves. If the outer band of the coin is obscured, tread is likely above 1.6mm. If the band remains visible, tread is insufficient and the tyre should be inspected and replaced.
Checking pressure
- Check when tyres are cold, before any extended journey.
- Obtain the correct pressures from the handbook or the label in the driver’s door shut or fuel flap.
- Include the spare, and note that loaded vehicles often require higher pressures.
Under-inflation accelerates wear, increases fuel consumption and impairs handling; over-inflation reduces grip. Correct pressure is, in effect, free safety.
Where a tyre is worn or damaged
Bald, cracked or bulging tyres require prompt replacement. FixMyTyreNow, a Londonos group company, fits replacement tyres at the customer’s home or workplace, so a failed check need not cost a working day. It is also worth understanding the difference between run-flat and standard tyres before purchasing.