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A little off the top - altering a vehicle’s mileage


WE’D all love to go back in time and we often reminisce about the past, but what if you’re an unsuspecting buyer of a used car, with an odometer that’s had the mileage reversed?

It’s not the most ideal way to reminisce because while dodgy salesmen can easily wind back 50 000km on the clock that mileage is real and so is the wear and tear the vehicle endured, racking up those kilometres.

The major benefits of dialling back a clock for a vehicle seller is they (of course), get to increase the value. Admittedly, this practise was more common with older vehicles, which still used analogue speedometers.

I remember trading in my old VW Fox a good few years ago. The engine was well run in as the car boasted over 300 000km on the clock. Admittedly there was nothing wrong with the Fox, I was just ready to upgrade.

After trading the car in I decided to see what sort of mark-up the dealership had placed on it. When I found it online, I saw it had had a haircut. My VW’s mileage was trimmed by over 150 000km and the dealership was now offering a well maintained car with relatively low mileage and a mark-up to match.

Because the car didn’t have any fancy Engine Control Units (ECUs) or modern tech, there was no real damage done to the engine. And it would only harm the next buyer who was fraudulently sold a vehicle with false mileage.

Mileage-altering is a lot more difficult to do today, thanks to the introduction of digital clocks in cars. But where there’s a will… there’s a way and it seems that even digital clocks can be altered. The repercussions, now, are a lot worse as this can affect crucial readings in the ECUs, which can potentially lead to safety issues, warns used car history experts, HPI.

As HPI states around 10 percent of all the modules in a modern car, such as the airbag, ABS and ignition, feed information into the central ECU system, and each time an event occurs – such as a faulty airbag warning – a ‘snapshot’ of the vehicle’s mileage will be recorded on these modules. Therefore, unless a vehicle’s mileage is wound back by a particularly ‘diligent’ and skilled clocker, who alters the mileage readings on all potentially affected modules in addition to the odometer, these will be out of sync, leading to issues with safety warnings – and potentially legal cases in the event of an accident.

Beyond this, important servicing and warning light indicators could be missed because the mileage has been reversed. In addition, the new reading will cause conflicts within the car’s electronics and interfere with the normal routines for servicing and repair, which will void the manufacturer’s warranty, should it be discovered that the mileage was altered.

Shane Teskey, Senior Consumer Services Manager for, explains further, “There’s also a very serious legal issue to be considered. In modern vehicles, crucial evidence of a car’s performance and speed at the time of an accident will be stored in the car’s on-board computer. Such evidence may have an important contribution to make in an accident investigation, but sadly, if a vehicle has had its mileage tampered with, the integrity of the data could be said to have been compromised and likely inadmissible as evidence in court. So innocent parties involved in accidents, could find themselves unable to prove this if they had been driving a clocked car without realising,” said Teskey.

So while many of us never knew that modern vehicles could have their mileage cut, it’s important to stay vigilant when purchasing a car. Often, if the mileage is too good to be true, it’s because it is.

We want to know if you’ve ever bought a car that’s had its odometer altered and how you found out.

Article written by Stuart Moir
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