There are only so many times you can take your vehicle to your local car mechanic in Reading for auto repairs before your motor will eventually need to be replaced… and it may well be that you decide to go down the secondhand route instead of investing in a brand-new set of wheels.

If that’s the case, you need to be well aware of the issue of car clocking, which involves changing the mileage displayed on the speedometer to convince potential buyers that the car has travelled less than it actually has.

You might well think that digital odometers would make it harder for unscrupulous car dealers to change the mileage but all that’s needed now for this to happen is a laptop and the right kind of software, which can tap into the electronic control unit of the car in order to bring the mileage right down.

In terms of assessing the value of a car, the mileage is in fact one of the biggest factors involved. When purchasing a used car, always make sure that you check its MOT history if it’s more than three years old. And always make sure that you check the service history before purchasing a vehicle so you know exactly what you’re spending your money on.

HPI recently designed an infographic to help people work out how to identify a clocked car, which could be worth looking at if you’re about to start shopping around for a new set of wheels.

It advises you to double check the odometer as this can be wound back for a viewing and then restored prior to pick-up, as well as checking the National Mileage Register (which has over 200 million mileage records on it) and trusting your judgement. If, for example, the car is 15 years old and only has 20,000 miles on the clock, then this might well suggest that all is not as it should be.

The company also has another infographic that showcases the true cost of car clocking, estimated to cost motorists £800 million each and every year. Of all the cars that HPI checks, one in 16 has a mileage discrepancy, which may be quite an alarming statistic if you are about to shop around for a secondhand vehicle.

While adjusting the mileage of a car isn’t illegal, knowingly selling one with false mileage is. In terms of the value of a car, the mileage really does affect it. So, for example, if you have a 2012 Ford Fiesta 1.25 Zetec that’s done 30,000 miles, it would cost you £4,650. But if it had done 90,000 miles it would cost you £3,225, so it’s certainly worth keeping an eye on that speedo just to be on the safe side.