Glossary
Odometer
The instrument that records total distance covered by a vehicle. Digital on every car built since the late 1990s.
Definition
An odometer is the instrument that records the total distance a vehicle has covered over its lifetime. On pre-1990s cars it was a mechanical drum driven by a flexible cable from the transmission; on modern cars it is a digital register stored in the instrument cluster, the gateway module, or both. Mileage is stored in kilometres in most of the world (and on the underlying memory of cars sold anywhere) and displayed in miles in the UK, US, and a handful of other markets. The legal status of the odometer reading is that it is the car's official mileage record — tampering is a criminal offence in every EU member state under the type-approval framework, and in the UK under the Fraud Act 2006.
Why it matters when buying a used car
The displayed odometer reading is the seller's claim about the car's mileage. A vehicle history report cross-checks that claim against independent inspection records — the gap between displayed mileage and historical mileage is the fraud indicator.
Often confused with
Mileage rollback
Tampering with a vehicle's odometer to display a lower mileage than the car has actually covered. A criminal offence in every EU country.
MOT
The UK's annual roadworthiness test, mandatory for cars over three years old. Records mileage and any defects on a public-access history.
HU
Germany's biennial roadworthiness inspection. TÜV is the largest of several authorised inspection bodies; HU (Hauptuntersuchung) is the formal name of the test.