A proposed EU ban on companies who provide mileage "correction" for cars should be retained by the UK and brought forward, the Local Government Association says.
Figures showed incidents of clocking - when a car's mileage dashboard display is decreased - rose by 10% between March and October last year.
The LGA also wants mileage correction devices to be banned.
An existing legal loophole means it is not illegal to alter a car's mileage.
It is fraudulent to knowingly sell a clocked car without disclosing that its odometer has been adjusted.
Adjusting the mileage can artificially increase car prices as well as hide serious mechanical problems on vehicles, the LGA warned.
Four members of a Birmingham family were jailed a year ago for "clocking" four million miles off vehicle odometers in what was described in court as "a professional operation".
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."
Motorists can check the mileage history of some vehicles recorded at each MOT with the Department of Transport.