Changelog

• 2026-08-03 — new report: MOT failure by fuel type. Electric, petrol, diesel and petrol-hybrid compared on the same age-standardised index, with the failure categories that separate them. Same release dvsa-2024-v1, no change to any previously published figure.
• 2026-07-30 — dvsa-2024-v1: initial release. 25 model families computed from 52,245,925 class-4 initial tests (66,857,355 total test records, calendar 2024). Frozen national age baseline published. Layers: identity & sample, age-adjusted index with CI, component failure and advisory anatomy, age curve, powertrain splits, mileage percentiles.

Baselines are frozen per release: statistics computed against dvsa-2024-v1 remain reproducible after later releases are published.