Clocking involves reducing the mileage of a vehicle by turning back the odometer. It is a common trick used by unscrupulous sellers to obtain a higher price and research shows that on average 1 in 12 vehicles have some sort of discrepancy. The average car does 10,000 to 12,000 miles per year, so if you think the mileage is inconsistent with the ag... Found on http://www.encyclo.co.uk/local/20538