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Odometer Fraud

That shiny used car with lower kilometres than normal may not be what it seems. It may have been "clocked", that is, had its speedo wound back to look like it has had an easier life. A recent investigation has revealed that "clocking" is rife in the Sydney motor trade at both private and retail levels. Winding back speedos in cars to make them more attractive to sell is a major part of the arsenal of dirty tricks used by unscrupulous car dealers, both licensed and otherwise. Tampering with odometers to make them show a false reading is illegal and criminal charges can result.

Today, it’s not unusual to see news reports of individuals being prosecuted for tampering with vehicle odometers (see related article). In Australia, much of the fraud is by not very sophisticated, low-level crooks (see related article). However, odometer fraud has probably been around since odometers were first fitted to vehicles. And contrary to popular belief, the introduction of modern hi-tech digital odometer displays eight years ago hasn’t stopped the practice. Experts say it has just made it more difficult. Old-style instruments are not difficult to wind back. On the other hand, it's a simple task to buy a second-hand, low-distance example from a wrecker and then fit it to a high-distance car.

With the digital odometer, the well-equipped tamperer now needs a computer, system interface and appropriate software rather than hand tools used to roll back the rotating number wheels on a mechanical odometer. More often than not they need an insider at a service department for the brand of car they intend to tamper with. Even without help, the software and system interface are not expensive and, insiders say, the car-hacker would recover the costs involved from the first couple of vehicles. In a digital odometer, the distance information is usually stored on a supposedly protected chip in the car's central processor. Yet a skilled computer operator can hack into the chip and reprogram it to display fewer kilometres the odometer will continue to work normally.

Other means of altering the displayed distance include connecting a cable directly to the speedometer chip but this requires removing the dashboard, disassembling the odometer, unsoldering the chip to reprogram it then reattaching it to its mount. Another method, also taking the dashboard apart, involves attaching a serial cable to the port at the rear of the odometer unit. Both rewinds are detectable and some manufacturers have built-in systems that show signs of tampering. Tell-tale signs include displaying unusual characters such as asterisks or a line of nines. A third method, more difficult to detect, uses the diagnostic computer plug fitted to an increasing number of cars to communicate with the central processor. In some cars, this plug can also be used to reprogram the odometer. The technology needed to manipulate digital odometers electronically is readily available from retailers, contained in dashboard recalibration kits.

There is usually little or no physical evidence to reliably confirm that an odometer has been tampered with. Even when there is, it can be difficult or impossible to determine who is responsible and when it occurred.  In most cases it is documentary evidence containing odometer readings, such as service records or registration transfers that proves the discrepancy.
Keeping in mind, an average fleet car will cover 20,000 to 25,000km a year, while a car used for private use will cover about 7,000 to 15,000 kms. It’s highly unlikely that an odometer of any sort will develop a legitimate fault that will cause its reading to decrease with vehicle use.

It is sometimes necessary to reset an odometer reading for legitimate reasons. An example would be fitting a new or replacement speedo to a vehicle. A second hand speedo from a wrecked vehicle can be used to replace a faulty unit. However if the odometer of the replacement is not reset to match that of the original, a record of the reason for the change and the differences in the readings should be kept and provided to purchasers to avoid allegations of fraudulent activity. The odometer should never be used as a gauge of vehicle condition.  A vehicle with a genuinely low odometer reading could still be in poor condition if it has been subjected to hard use. There is no substitute for an independent vehicle inspection to determine a vehicle’s overall condition.When purchasing, wherever possible compare the vehicle’s odometer reading against any available records. These could include documents such as Inspection Certificates (pink slips), previous sales contracts or service records.

Fines for clocking are high; courts can impose penalties of up to $11,000 for each car whose odometer has been interfered with. But in many cases, the rewards appear to outweigh the risks. The NSW courts are prepared to come down heavily on clocking offenders, yet in the first instance it is a case of buyer beware, especially if the car is bought privately from a seller whose bona fides are not known. However, if there is any suspicion, a mechanical inspection should determine whether the wear and tear on a car matches the distance shown on the odometer. If it's not, steer clear.

You can also check out the Buyer's Guide page for more detailed information.


Fair Trading. (2013). Odometer fraud lands unlicensed dealer $31,000 penalty. Retrieved from

The Royal Automobile Club Queensland. (2013). Odometer Fraud. Retrieved from

The Motor Report. (2013). Odometer Tampering: Prison And Fines For Unlicensed NSW Dealer. Retrieved from


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