Miles or kilometres? Avoid a false mileage discrepancy
By Plateworthy · Updated · Editorial policy
A smaller number does not necessarily mean a lower distance when the unit changes. Check the original units before comparing the odometer with MOT, service or auction records. Keep the original reading alongside any converted value.
Use one comparison unit, retain the originals
One mile is 1.609344 kilometres. Divide a kilometre reading by 1.609344 to compare it in miles. Thus 120,000 kilometres is about 74,565 miles; a later reading of 75,000 miles can fit an increasing distance sequence.
Label converted figures as approximate and do not round them into apparent precision. If the unit is absent, ask for the original document instead of choosing whichever unit removes the discrepancy.
Check why the unit changed
Ask whether the vehicle was imported, whether the displayed unit can be switched and whether the instrument cluster has been replaced. Request dated records identifying the car and supporting the explanation.
The ability to switch a display today does not prove which setting was used for an earlier entry. Compare the actual record at that time. A unit change and an incorrect reading can also occur in the same history.
Compare maintenance on a consistent basis
Once the timeline is understood, compare the manufacturer’s maintenance guidance using the correct distance unit and elapsed time. A service interval expressed in kilometres should not silently become the same number of miles.
Pass the original and converted timeline to anyone inspecting the car. If the evidence is insufficient, describe the history as unconfirmed rather than presenting a conversion as proof that every reading is accurate.
Common questions
- Should I convert a record when the unit is unknown?
- Keep it unconfirmed until the original unit is established. A plausible conversion is a hypothesis, not evidence of the original unit.
Sources and further checks
Primary guidance checked for this update. Rules and individual circumstances can change; use the linked official service or advice where a decision depends on it.