Your vehicle odometer is tamper-resistant. You may wonder what happens if a vehicle has to have a new odometer installed. If possible, or when regulations require, the new one has to be set to the same reading the old had. If the odometer cannot register the same mileage as before, it should be adjusted to read zero. A label should then be attached to the driver's door frame indicating, in writing, the prior mileage and date of repair or replacement. If the mileage is unknown, the label should indicate "previous millage unknown."