Official fuel economy comes from a laboratory. These figures come from owners. Real-world MPG by engine for 776 models across 48 makes, built on more than 319,000 owner submissions, with the official NEDC and WLTP figures alongside so you can see the gap. Free, no sign-up, and you can add your own car’s figure.
If you used the Honest John Real MPG section before the site closed in 2026, this is where that information now lives. We rebuilt it from the archived Honest John dataset and other sources: the official NEDC and WLTP figures for every engine, the owner-reported averages the archive held, and new submissions from CarAdCheck readers, which keep the averages improving. Each model page links to the archived page it was built from.
CarAdCheck is not affiliated with Honest John or Volkswagen Financial Services. How we rebuilt Real MPG, and how to add your car.
Real MPG is the fuel economy owners actually get, engine by engine, set against the official laboratory figure. The official number is what the car managed on a test cycle; the real number is what people report from the road. The gap is usually 10 to 30 per cent and varies a lot by engine, which is why it is worth checking before you buy.
Honest John closed in August 2026 and its Real MPG section was retired with it. This section is where that data now lives: we rebuilt it from the archived Honest John dataset, kept the official NEDC and WLTP figures alongside the real-world averages, and reopened submissions so the figures keep improving. It is free and stays free. CarAdCheck is not affiliated with Honest John or Volkswagen Financial Services.
Real average divided by the official combined figure for that engine. Where the official figure is a range, the midpoint is used. Figures marked with an asterisk are measured against the WLTP figure rather than the older NEDC one, which is why they can look higher.
Yes. Every model page has a short form: pick the generation and engine, enter what your car does, say what kind of driving you do. No postcode, no account. Submissions are checked and folded into the averages in batches.
Fuel economy is one line on the running-cost sheet. These cover the rest of buying a used car without getting stung.