Part-worn tyres

A dangerous false economy

With the prices of new car tyres continually on the increase, low-cost part worn tyres can sound like a good idea. In fact they are not only a false economy but can be dangerous.

Strict regulations govern the sale of used tyres and the conditions in which they can be sold. There are many aspects that can make a tyre unsafe or illegal. Old tyres, regardless of their appearance and tread depth, can pose a major threat to safety. That’s because tyres deteriorate from the inside as well as wearing from the outside. Oxidation of the internal components causes tires to break down from the inside out. A tire may look fine on the outside, but as tyres age their material and chemical properties change, increasing the risk of the catastrophic tread and the belt separating – with potentially disastrous results.

Unaware of the state of the inside of the tyre, most consumers focus on the tread depth – the measurable value of the tyre. Tyres must have 2 mm of tread across the width and radius. The legal limit is 1.6mm with new tyres having 8mm. For the sake of providing an economical product, many used tyres only just meet the legal standard. It would be more accurate to describe part-worn tyres as “nearly worn out tyres”, which is more honest, doesn’t sound so good.

There are many things that can affect a tyre and its performance other than those covered directly by the law; UV light and ozone exposure, exposure to chemicals, tyre age and previous use are just a few examples. It is much more likely that a used tyre has been affected by these than a new tyre. At the same time the user still has to pay for wheel balancing for a tyre that will not last much longer – another false economy. Part-worn tyres – you pay more but get less:

  • A new tyre has 8mm when new so has 6.4mm of “useable” tread.
  • Most part worn tyres are supplied with 3mm. This gives 1.4mm of “useable” tread.
  • If a new tyre costs £50.00 this equates to £7.81 per mm.
    An equivalent part-worn tyre would cost only £25 but would equate to a huge £17.86 per mm!Tyre use is governed by The Motor Vehicle Tyres (Safety) Regulations 1994. S Part 2 Section 7 covers the use of part-worn tyres. To find out more about the law go to