USED car buyers have been warned to beware of shonky sellers winding back odometers, with a report revealing tens of thousands of used cars have been "clocked".
The illegal practice is most common in South Australia, Tasmania and Queensland where one in 100 vehicles has been tampered with, according to consumer vehicle research site carhistory.com.au
The site found that in the year to March, just under 1 per cent of used cars it checked had odometers wound back which, if representative of the national used car market, meant tens of thousands of vehicles were being sold under false pretences.
Carhistory boss David Scognamiglio said the report indicated that every state had groups of shonky sellers who had evaded detection and prosecution for misrepresenting odometer readings.
"Many sellers fail to provide statutory warranties and falsify log books and other documents to car buyers," he said.
"No one wants to buy a car to find out in the next few months that they've been ripped off, the warranty is void or they are having issues due to the vehicle's extensive use."
Individual offenders face up to two years in jail and fines of $40,000 to $60,000, depending on the state, while organisations face fines of about $200,000.
Two years ago, Operation Turner collected $400,000 in fines from 13 Queensland offenders detected, Mr Scognamiglio said.
Carhistory's new report uncovered dozens of shocking examples of fraud, including:
A Lexus coupe found by a buyer to have been wound back 70,000km.
Another motorist lost their $50 deposit after backing out of a sale when they discovered a repairable write-off that should have had a 190,000km reading showed only 125,000km during a test drive.
Mr Scognamiglio warned "clocking" could even endanger lives, with mechanical issues more likely to be overlooked as unsuspecting owners were misinformed about the service history of their car.
"Owners are clearly getting ripped off, paying too much for their car, as well as having to deal with more common breakdowns due to extra wear and tear of their vehicles," he said.
"The best way to protect yourself from getting ripped off is to get an independent inspection by a mechanic, check logbooks, do a finance check and also get a car history check, which is the only vehicle report that covers odometer readings."
Mr Scognamiglio also warned that if buyers did not check the odometer reading when they bought a car, they could be accused of being the "clocker" if they later sold the vehicle.
He said modern, digital odometers were not tamper-proof.