Known faults, Real MPG and MOT pass rates, by model
The data our reports are built on, published on free pages so anyone can check it. One page per model in each section, and every page links to the same car in the others, so you can go from what goes wrong, to what it really does to the gallon, to how it fares at the MOT.
Common problems by model
126 modelsKnown faults with symptoms, repair costs, the advert phrases sellers use to hide them, and the confirmed service intervals for the engine.
Real MPG by model
510 models · 319k submissionsWhat owners actually get to the gallon, engine by engine, against the official NEDC and WLTP figures. Add your own car’s figure.
MOT pass rates by model
coming nextPass rate by age and the most common failure reasons for each model, from the DVSA’s published MOT results.
Where this data comes from
Three sources, credited on every page: our own research into each model’s known faults, including specialist and owner-club sources and DVSA recall data; the archived Honest John dataset, which we recovered after the site closed in 2026 so its owner reports and Real MPG figures did not vanish with it; and submissions from CarAdCheck readers. The same data feeds our free advert check, which reads a listing against it for the exact engine and year.
CarAdCheck is not affiliated with Honest John or Volkswagen Financial Services.
Buyer's guides
The data tells you about the model. These cover the rest: the checks, the paperwork and reading the advert.