MOT Advisory: Tyre Worn Close to the Legal Limit (1.6mm)

What this advisory means

An advisory is recorded when an item is not deteriorated enough to justify a fail, so it informs the presenter of a developing issue. Advisories do not cause a fail and are recorded in the MOT history. The note about tyre tread worn close to the legal limit therefore signals that a tyre is approaching, but has not yet reached, the point at which it must be rejected.

For cars with up to 8 passenger seats, tyre tread must be at least 1.6mm deep in the primary grooves across the central three-quarters of the tread width and around the entire circumference, as set out in DVSA manual 5.2.3. Tread below this limit is a dangerous defect. The advisory reflects a measurement close to that threshold rather than one beneath it.

The note does not change the vehicle's pass result and does not itself require any repair. It remains on the MOT history as a record for the presenter. Because tread below 1.6mm is a dangerous defect, the advisory indicates a tyre that is near the legal minimum and may reach it before the next test.

When it becomes an MOT fail

A tyre worn close to the legal limit is recorded as an advisory while the tread remains at or above 1.6mm in the required areas. The advisory becomes a dangerous defect when the tread is below 1.6mm deep in the primary grooves across the central three-quarters of the tread width and around the entire circumference. This threshold applies to cars with up to 8 passenger seats and is set out in DVSA manual section 5.2.3.

The defect category matters because a dangerous defect means the vehicle fails the MOT and must not be driven on the road until it is repaired. The manual reference for the tread depth requirement is 5.2.3, and the same section covers the condition that turns the advisory into a fail. A tyre that is obviously under-inflated is treated separately as a minor defect under 5.2.3 l.

In practice, the advisory stops being advisory at the point the measured tread falls below 1.6mm in the specified grooves and across the central three-quarters of the tread width around the entire circumference. At that point the DVSA manual classifies the tyre as a dangerous defect rather than a minor one. The distinction rests on the measured tread depth against the 1.6mm limit, not on how the tyre looks or how it is inflated.

Source: DVSA manual section 5: tyres, checked 23 October 2026.

Frequently asked questions

What does an MOT advisory for a tyre worn close to the legal limit mean?

An advisory is used when an item is not deteriorated enough to justify a fail, to inform the presenter. It does not cause a fail and is recorded in the MOT history. In this case the tyre tread is close to but not below the legal minimum.

What is the legal tyre tread limit for cars?

For cars with up to 8 passenger seats, tyre tread must be at least 1.6mm deep in the primary grooves across the central three-quarters of the tread width and around the entire circumference, as set out in DVSA manual 5.2.3.

Does an advisory for tyre tread cause an MOT fail?

No. Advisories do not cause a fail. The advisory is recorded to inform the presenter that the tyre is worn close to the legal limit, and it appears in the MOT history for the vehicle.

What happens if tyre tread falls below 1.6mm?

Tread below 1.6mm is a dangerous defect under DVSA manual 5.2.3. This is treated differently from an advisory, which applies only when the item is not deteriorated enough to justify a fail.

Is an under-inflated tyre recorded as an advisory?

A tyre obviously under-inflated is a minor defect under 5.2.3 l, not an advisory. This is separate from the tread advisory, which concerns wear close to the 1.6mm legal limit.