Part Worn Tyres vs. New Tyres

They may seem like a cheap alternative, especially if your car has seen better days, but part worn tyres are a potential accident in the making.

Tyres are extremely important in keeping you and fellow motorists safe on the road. They are the only part of the car in contact with the road and so a lot relies on their condition.

Did you know: each year in the UK more than 1,200 motorists are injured in an accident where illegal, defective or under-inflated tyres are a contributory factor (source: TyreSafe).

Should You Buy Part Worn Tyres?

In the UK it is not illegal to sell a part worn tyre. Legislation has been put in place to permit the sale, subject to the tyres meeting a number of strict criteria. However, the number of part worn tyres sold illegally is worrying and poses a serious safety risk to motorists.

A campaign carried out by TyreSafe discovered that 98% of part worn tyres they checked were sold illegally - with 34% of the tyre containing dangerous forms of damage.

At we feel very strongly on this subject and actively encourage motorists to purchase new tyres.

Trading Standards

To protect motorists, trading standards have defined the legal expectations of a part worn tyre.

Part worn tyres must:
  • Have an EC approval mark and a speed & load capacity index
  • Be marked with 'PART-WORN' in upper case letters at least 4mm high.
  • Not have a cut over 25mm or 10% of the section width of the tyre
  • Not have any internal or external lump, bulge or tear
  • Not have any ply or cord exposed
  • Not have any penetration damage that has not been repaired
  • the original tread pattern of the tyre must be at least 2mm deep

Although these rules have been put together to try and help regulate the sale of part worn tyres, the fact that a tyre, which has previously been damaged and then repaired, is ok to sell should raise eyebrows.

If you have looked into buying part worn tyre and believe that the tyres that were up for sale did not comply with the legislation, it would be advisable to contact Trading Standards.

Hidden Dangers of Part Worn Tyres

One of the main reasons is the potential dangers that lurk within the internal structure of a used tyre. Although the tyres do need to meet certain regulations, the test which take place when a part worn tyre is put through to deem whether it is safe for reselling does not make use of any x-ray machinery and as such it is impossible to tell what unseen damage may have occurred.

Most part worn tyres are imported, mainly coming from continental Europe, with many coming from Germany where the legal minimum tread depth is 3mm. They tyres are typically sold with around 50% of the original tread depth – meaning they have often been used for several thousand miles prior to the sale.

It is hard to know the full history of a part worn tyre. You can never truly know how often they have hit kerbs, been run with the wrong air pressure, or if there is any irreparable invisible damage.

False Economy of Part Worn

The cost of a part worn tyre is, at first sight, lower than that of a new tyre. The very nature that they are a used product reflects this.

However, despite the initial cost, part worn tyres do not offer good value for money in the long term.

Given the fact that a part worn tyre has already been used, they come with significantly less tread depth than a new tyre. A part worn tyre typically has 4mm and under, whereas a new tyre on average comes with 8mm of tread.

Rather than just considering the initial purchase price, drivers should look at the cost per mm of a tyre.

When purchased a part worn tyre may have as little as 2mm of tread. In the UK, the legal minimum tread depth of a tyre is 1.6mm across 75% of the circumference of a tyre. So it would not be long before another new set of tyres was required.

Tyre Safety

Tread depth is one of the key components for safe driving, especially on wet road surfaces. The grooves in a tyre aid in dispersing water from between the tyre and road surface.

If a tyre has lower tread depth, then it becomes increasingly ineffective at removing the water. This in turn leads to increased braking distances and a higher risk of aquaplaning.

When the British Tyre Manufacturers' Association, conducted tests on the performance on tyres with different levels of tread depth, the braking distance in wet weather for a tyre with the minimum legal limit of 1.6mm was almost 12m longer than a new tyre (at 50mph).