Tyre Checks Before MOT: Tread, Pressure, Damage & Wear

Legal tread depth — the 20p test

UK law requires at least 1.6mm of tread across the central three-quarters of the tyre, all the way round. Slot a 20p coin into the main grooves — if you can see the outer band of the coin, the tyre is at or below the limit.

We replace at around 3mm. Below that, wet braking distance more than doubles compared to a fresh tyre — and the MOT doesn't care that 'it was fine last week'.

Uneven wear — what it tells you

Replacing tyres without fixing the cause means burning through the new ones in months. We check tracking and suspension as part of any tyre fit.

• Inner edge worn: tracking out, worn lower arm bushes or tired anti-roll links
• Outer edge worn: under-inflation or hard cornering
• Centre strip worn: over-inflation
• Feathered / cupped wear: failed shock absorber on that corner

Sidewall damage and lumps

Any cut, bulge or visible cord on the sidewall is an automatic MOT fail and means the tyre needs replacing — not repairing. Pothole damage and kerb impacts are the usual culprits in Poplar and on the Isle of Dogs.

Pressures — quick check

Correct pressures are on a sticker inside the driver's door shut or in the fuel-filler flap. Check cold, ideally before a long drive. Underinflation kills MPG and overheats tyres; overinflation reduces grip and wears the centre strip.

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