How mileage affects MOT failure rates
20 June 2026·4 min read·Updated 10 August 2026
Failure rates climb with the odometer
National MOT data shows failure rates rising with recorded mileage. Cars under 20,000 miles fail least, cars past 100,000 fail most. The full band-by-band chart is on the MOT failure rates by mileage page.
The reasons are straightforward. Tyres, brakes and suspension are wear items measured in tens of thousands of miles, and high-mileage cars that reach the test on original parts fail on those parts.
Mileage history matters more than the headline number
How the miles were reached matters as much as how many there are. Dips, gaps and low readings between MOTs point to a clocked or swapped odometer, and that discrepancy is a better warning than the final figure.
Roadworthy's check compares every MOT odometer reading with the one before it and flags the ones that do not add up, so you see the issue before you buy.
What high-mileage owners can do
High-mileage cars do not have to fail. A 100,000-mile car with fresh bushes, brakes and a recent belt service passes most years. The national figures describe the average, not your car.