MOT Failure Rates by Car: How to Read the Data
AutoSafe's comparison artifact contains aggregated official MOT records grouped by model family, age band and mileage band. Those records can show how groups performed historically. They cannot establish the present condition or next result of one submitted vehicle.
Interpretation boundary: the 26.9% figure is a dataset reference, not a result for your car. A physical inspection and the official MOT are the only ways to assess its current condition and test outcome.
Why model, age and mileage matter
A model-wide average can hide material differences between newer and older vehicles. AutoSafe therefore starts with the narrowest supported group: model family, age band and available mileage band. If that cohort has no usable evidence, the report broadens to age-only, then model-wide, then the dataset reference, and labels the scope used.
Recorded rates by age band
These are exact weighted aggregates from the checked-in artifact. The bands are dataset groups, not promises about an individual vehicle.
| Age band | Recorded tests | Recorded failure rate |
|---|---|---|
| 0–2 years | 8,335,239 | 11.52% |
| 3–5 years | 33,562,625 | 14.60% |
| 6–10 years | 52,383,079 | 25.04% |
| 11–15 years | 33,834,406 | 38.07% |
| 15+ years | 20,394,536 | 39.78% |
Age composition is one reason simple “best model” rankings can mislead. A model dominated by newer vehicles is not directly comparable with one dominated by older vehicles. AutoSafe therefore does not use this static guide to make a durable best/worst recommendation.
Dataset-wide component context
The source artifact also contains component-category rates. These weighted aggregates show how often recorded tests involved each category across the dataset. They are not diagnosed faults.
| Component category | Weighted recorded rate |
|---|---|
| Lamps, reflectors and electrical equipment | 5.57% |
| Suspension | 4.28% |
| Brakes | 3.44% |
| Tyres | 2.96% |
| Visibility | 2.34% |
| Body, chassis and structure | 1.74% |
| Steering | 0.94% |
How to use a comparison responsibly
- Check the evidence scope and sample count before reading the percentage.
- Treat estimated mileage differently from an observed MOT odometer reading.
- Do not interpret component patterns as faults on the submitted car.
- Use GOV.UK's official service for the authoritative MOT history.
- Arrange a physical inspection if you need a condition assessment.
Compare a vehicle with the recorded cohorts
See the latest recorded details, mileage provenance, evidence scope and comparable-vehicle failure rate.
Enter a registrationMethodology and provenance
The primary artifact is prod_data_clean.csv.gz. Its 254,145 cohort rows sum to 148,509,908 tests and 39,969,903 failures. Overall and age-band rates above use total failures divided by total tests. Component rates use sample-size weighting. The release claim sweep recalculates the totals from the gzip CSV and fails if the contract metadata or public dataset-size claim drifts.
Frequently Asked Questions
Which car has the lowest or highest MOT failure rate?
A durable ranking needs careful control for age, variant mix, sample size and data quality. Use the live make/model pages for current recorded cohorts; do not treat a low group rate as a condition assessment or buying recommendation.
Do older groups record more failures?
In this artifact, the weighted rate rises from 11.52% for the 0–2 band to 39.78% for the 15+ band. That is a group-level association and does not determine any individual vehicle's result.
Can AutoSafe predict whether my car will pass?
No. AutoSafe reports recorded details and comparable-vehicle evidence. It does not inspect the car or determine its next MOT result.