Why cars fail their MOT on tyres (the most dangerous failure)

Tyres are the third most common MOT failure at 6.23 percent, but cause 60 percent of dangerous defects. Cheap to fix, vital to check on any salvage buy.

MOT DATA · 4 min read

Common and genuinely dangerous

Tyres fail 6.23 percent of car MOTs, which puts them third overall. But they punch far above that on safety: tyres account for 60.32 percent of every dangerous defect the DVSA records. So while they are cheap to sort, they are the single most likely thing to make a car genuinely unsafe.

What fails

The usual causes are tread below the 1.6mm limit, uneven wear from tracking or suspension problems, perished or cracked sidewalls, cuts, bulges, and the wrong tyre sizes or ratings fitted. Uneven wear is worth noting because it often points at an alignment or suspension fault underneath.

What it costs

A budget tyre is thirty to sixty pounds fitted, a premium tyre more. This is one of the cheapest fixes on the whole failure list, which is why a car failing only on tyres is rarely a problem. The only sting is a car needing a full set of four, or oddball and large-diameter tyres that cost a lot more each.

The salvage angle

On a salvage car, tyres are cheap and expected, so they should not put you off. But uneven wear is a clue: if the photos or the failure sheet show one edge gone, suspect tracking or a bent component from the incident, which is the real cost. Budget a set of tyres as standard and treat uneven wear as a prompt to look harder at the suspension.