A misrepresented odometer can cost you money if you proceed unknowingly into a sale. An automobile with high mileage will have a lower value than one with a relatively small number of miles. A higher-mileage car will likely incur greater maintenance costs, as its extended use would wear out parts that would need to be replaced or repaired. Checking the odometer reading can be a time-consuming, but necessary, step to ensure someone hasn't tampered with the reading to sell you an inferior car for a superior price.
Ask to see the title and maintenance records for the vehicle. The title will list the mileage and the date the title was issued. Frequently, maintenance records, especially when produced by service technicians, will also contain mileage readings. You might also find mileage information on stickers left on the window or door frame from the last scheduled oil change.
Verify that these numbers make sense. For example, if the title was issued three years ago and listed the vehicle as having 80,000 miles, you know something is wrong if the odometer reading is now at 30,000. Likewise, six scheduled oil changes within 6,000 miles is also way off, since most manufacturers recommend an oil change only once every 3,000 to 5,000 miles. These numbers simply do not add up.
Look closely at the odometer, assuming it is a traditional rolling style. Any misalignment in the numbers could indicate tampering.
Test drive the car and watch the odometer. If the odometer numbers don't move or the owner says it's simply broken, then you know you can't trust the reading.
Examine the car for areas -- tires, pedals and sometimes seats -- that are typically worn away with age. Heavy wearing, such as bald tires, on a low-mileage vehicle could indicate that either the odometer is inaccurate or the driver has been abusive to the vehicle. In either case, you might not want to purchase the vehicle.
Check Carfax for a free odometer report (see Resources). Although there are other services offered for a fee, an odometer check on this website is free. This method is not guaranteed to catch all faults, since not all vehicles are in the Carfax system and not all mileages are recorded past the title date.