# Which cars reach the test in best shape

> Failure, rectification, age and mileage for the fifty most-tested class 4 models in London postal districts.

- Category: Transport
- Cadence: annual
- Status: Published on a annual cadence.
- Dataset key: `mot-by-model`
- Source: [DVSA](https://open.data.dvsa.gov.uk/mot-anonymised/index.html)
- Licence: Open Government Licence v3.0 — [terms](https://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/)
- Canonical page: [https://londongraph.com/g/which-cars-reach-the-test-in-best-shape](https://londongraph.com/g/which-cars-reach-the-test-in-best-shape)
- Machine-readable record: [https://londongraph.com/data/which-cars-reach-the-test-in-best-shape](https://londongraph.com/data/which-cars-reach-the-test-in-best-shape)

## Methodology

DVSA anonymised class 4 initial-test results grouped by the recorded make and model for the eight London postal areas. A minimum of 500 tests is required and the fifty highest-volume models are retained for each year. THIS IS NOT A RELIABILITY LEAGUE TABLE: a model's crude failure rate is strongly affected by the age and accumulated mileage of the vehicles that reached the test, maintenance and who keeps them. The page therefore places failure beside mean age, mean odometer reading and Pass with Rectification at Station. Model names are administrative source labels and can contain variants. The tested fleet excludes most vehicles under three years old.

## Visualisations

- [Model distribution](https://londongraph.com/g/which-cars-reach-the-test-in-best-shape): Place high-volume models in the crude failure-rate distribution with exact test counts.
- [Age vs failure](https://londongraph.com/g/which-cars-reach-the-test-in-best-shape?view=age): Compare each model's mean tested age with its crude failure rate. Caveat: Association does not isolate vehicle reliability, servicing or keeper behaviour.
- [Mileage vs failure](https://londongraph.com/g/which-cars-reach-the-test-in-best-shape?view=mileage): Compare mean recorded odometer with crude failure rate. Caveat: Odometer is accumulated mileage at test, not annual distance driven.
- [Model profile](https://londongraph.com/g/which-cars-reach-the-test-in-best-shape?view=model): Inspect pass, rectification, failure, age, mileage and sample size together.

## Citation guidance

Attribute the original publisher named above and identify LondonGraph as the visualisation and methodology layer. Do not describe live values as a historical census, and do not present placeholder values as observations.