To charge borrowers for the distance they have driven, we do not read the car's odometer: rather we use the GPS device that is fitted to the car and which is a more accurate measure.
Speedos and by extension, odometers, can be inaccurate by up to 10% (read more here) and may depend on things such as on how well tuned the car is or the circumference of the tyres.
If you would like to double-check that you have been billed for the right distance, you might like to plot your trip on Google Maps and use that as a secondary source of comparison.
Did you take a ferry on your trip?
If you intend on travelling on a ferry with the car please inform the owner of the car for permission and contact our support team in advance (email is ok if enough advance warning if provided). We don't intend to add distance you didn't drive to your trip!