Home › Used car model guides › Methodology
How Check My Vehicle calculates the MOT pass rates, failure areas, mileage and recall counts shown in its used-car model guides.
Data sources
| Dataset | Details | Licence |
|---|---|---|
| dvsa mot | DVSA anonymised MOT tests and results, 2025 extracts (dft_test_result_extracts_2025.zip, dft_test_item_extracts_2025.zip; S3 Last-Modified 19 Jun 2026; downloaded 14 Oct 2026) https://edh-dvsa-data-gov-uk-files-prod.s3.eu-west-1.amazonaws.com/ | Open Government Licence v3.0 |
| dft veh0120 | DfT/DVLA df_VEH0120_UK (licensed and SORN cars by make and model), 2026 Q2 column | Open Government Licence v3.0 |
| dvsa recalls | DVSA vehicle recalls RecallsFile.csv (S3 Last-Modified 14 Oct 2026 04:03 BST; downloaded 14 Oct 2026) https://www.check-vehicle-recalls.service.gov.uk/documents/RecallsFile.csv | Open Government Licence v3.0 |
Population
class 4, test_type NT, result in P/F/PRS, test_date in 2025; first_use_date year 1971 and invalid/future years dropped
Definitions and formulas
- pass rate: P / (P+F+PRS)
- initial fail rate: (F+PRS)/total
- benchmark: sum over first-use years of (model tests in year x all-class-4 pass rate for that year) / model tests
- delta pts: model pass rate – benchmark, percentage points
- failure area: distinct initial tests with >=1 F or P (PRS) item in the top-level group / total initial tests
- top items: same metric by rfr_id, top 10 with incidence >=0.5%
- advisories: rfr_type A, top 5
- mileage: median test_mileage by age (2025 – first-use year), ages 3-15, mileage>0, n>=500
Suppression rules
{"by_year_row_min_n":500,"mileage_age_min_n":500,"model_min_tests":1000}
Known limitations
- Make and model are matched from DVSA text fields; some misspelt makes are not included.
- First-use year 1971 is a DVLA placeholder and is excluded.
- MOT results describe tested cars, not overall reliability, and say nothing about any individual vehicle.
- Recall counts are text matches at campaign level and may not affect every car.
Updates and corrections
Figures are refreshed when DVSA and DfT publish new data. To report an error, use the contact page.
Attribution
Contains public sector information licensed under the Open Government Licence v3.0. Source: DVSA anonymised MOT test data 2025; DfT/DVLA vehicle licensing statistics (VEH0120); DVSA vehicle recalls data. Not endorsed by DVSA, DVLA or DfT.
Last updated 15 October 2026 · Written by Kate