A surge in car clocking has seen rogue dealers knock millions of miles off odometers, leaving owners defrauded and facing potentially serious repair bills, councils have warned.
The Local Government Association (LGA) has called for a proposed EU ban on companies who provide mileage "correction" to be retained under UK laws and brought forward after latest figures showed clocking increased by 10% between March and October last year.
The crime can defraud buyers by artificially increasing car prices as well as hide serious mechanical problems on vehicles and lead to expensive repair bills, the LGA warned.
An existing legal loophole meant that while knowingly selling a clocked car without disclosing it was fraudulent, it is not illegal to alter the odometer's mileage.
The LGA is also calling for mileage correction devices - widely available for sale online for about £120 - to be banned.
Five men from the same family were recently jailed for a total of 18 years and three months for conspiring to clock more than four million miles off cars, lowering odometers by as much as 125,000 miles.
Nottingham City Council Trading Standards investigated two car dealers who were each jailed for 15 months after clocking 13 cars by more than one million miles after a consumer raised a complaint.
In another case, a dealer sold an Audi TT with the mileage advertised incorrectly as 79,000 when it was actually 147,464.
The LGA said taking 60,000 miles off a Range Rover Evoque or an Audi A3 increased their value by £4,000, and doing the same to a Nissan Qashqai or Volkswagen Golf upped their price by around £3,000 and £2,500 respectively.
Simon Blackburn, chairman of the LGA's Safer and Stronger Communities Board, said: "With up to 1.7 million clocked and potentially dangerous vehicles on UK roads, anyone buying a second-hand car should make as many checks as they can to ensure that the vehicle is showing its true mileage.
"Clocking is harming both reputable used car dealers and consumers, and unless the proposed EU ban on mileage correction services is brought forward and made part of UK law, thousands more cars will continue to be clocked over the next two years, jeopardising the safety of cars on UK roads."
The LGA advised buyers to check with the DVLA for previous MOTs showing the car's mileage, the service history for steady mileage increases and the steering wheel, driver's seat and pedals for wear that is disproportionate to the claimed mileage.
Anyone who suspects they have bought a clocked car should contact Citizens Advice on 03454 04 05 06.