Nearly 200,000 cars have their odometers rolled back every year, according to a new study from Carfax.
This may cost victims more than $760 million in lost value and unexpected repairs.
Carfax said consumers in Calif., Nev., Mass., New York and Texas are the most at risk.
"There are serious problems that can arise from a rollback," said Larry Gamache, communications director at Carfax. "Older, deteriorating parts lead to unexpected repairs while unperformed maintenance for the true mileage may compromise the safety and performance of these cars."
Older cars, those 14 to 15 years old, are rolled back most often. The study found that most rollback result in at least 50,000 miles taken off the odometer.
Odometer correction tools are easy to find online and use on digital odometers illegally. The altered cars are often sold through online ads and private sales, though some are traded in, Carfax said.
Carfax offers these tips to avoid buying a rolled back car:
- Compare the car's wear and tear to the odometer reading
- Ask the seller for service records and note the mileage readings
- Buy from a trusted source or recommended dealer
- Be wary of sellers who want a quick sale or a deal that seems too good to be true
- Get the vehicle's history from the seller or at Carfax.com.
- Have a trusted mechanic inspect the vehicle and check its computer