A survey of used tyres - often called part worn tyres - has shown that many are potentially dangerous.

TyreSafe (a not-for-profit organisation) carried out a study which involved the purchase of 50 random part worn tyres from retailers across the UK. It found that 98 per cent were being sold illegally as they did not meet current requirements, but more seriously, over a third of the tyres were found to contain potentially dangerous forms of damage or non-compliance.

"Despite clear legislation it would appear from our investigation that the sale of illegal part worn tyres is a very real problem and needs to be tackled head on by Trading Standards as a matter of urgency. Those who sell illegal part worn tyres need to be educated and stopped as it really it could be a matter of life and death," said Stuart Jackson, chairman, TyreSafe.

One tyre in its investigation was described as having the "potential to kill" as it still contained a metal object penetrating 5cm through the tread in a manner which was likely to result in sudden and total tyre failure had it been fitted to a vehicle.

Other serious safety breaches included dangerous and unsafe repairs, exposed cords, bead damage and evidence of runflat damage. TyreSafe says that, last year, there were more than 1,200 road casualties where illegal, defective or under-inflated tyres were a contributory factor.

We have to agree. We know new tyres are expensive – and as cars have ever wider tyres, the prices keep going up - but part-worn tyres are a gamble. A part-worn tyre could come from a legitimate source, but most people use their tyres until they are worn out and then replace them. How many MOT failures, for example, have tyres in good condition that you would be happy to use? Given the difference in how long a new tyre will last, you will normally get your money back in the long run. Read our piece on how to choose a new tyre here.