Should You Buy Part Worn Tyres?

Part worn tyres may, on the face of it, seem like a cheaper alternative. However, part worn tyres can also be a potential accident waiting to happen.

It is no secret that tyres are one of the most important parts of a car when it comes to keeping you and fellow motorists safe. After all, tyres are only part in contact with the road.

Selling part worn tyres in the UK is not illegal - in fact, special legislation exists that permits the sale, if the tyres meet specific strict criteria. 

The UK legal requirements for selling part-worn tyres are defined by Trading Standards and include having an EC approval mark, being marked with "PART-WORN" in letters at least 4mm high, and ensuring the tyre has a minimum of 2mm tread depth.

That being said, the number of part worn tyres sold each year in the UK illegally is worrying.

A campaign by TyreSafe – a UK charity dedicated to raising awareness of the importance of correct tyre maintenance - carried out undercover investigations into the sale of illegal part worn tyres in 2018. 

Of the 129 tyres they investigated, from 68 part worn tyre dealers, it was found that 75% were unsafe and not fit for road use. 

Part Worn Tyres: Trading Standards

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
• Have had at least a 2mm deep original tread pattern

It is crucial that such rules exist, given that unsafe tyres contribute significantly to road accidents. For instance, in 2023, there were 1,695 road deaths in the UK, with 28,967 serious injuries—many of which were linked to poor tyre conditions, including the use of unsafe part-worn tyres

The (Literal) Hidden Dangers of Part Worn Tyres

Although legal part worn tyres are required to meet regulations, the tests that are carried out to determine if the tyre is safe does not use x-ray machinery. 

As such, it is near impossible to deem whether any unseen internal damage has occurred.

Part worn tyres are typically sold with around 50% of the original tread depth. 

This means that the tyres have been driven on for several thousand miles prior to the sale.

With this amount of road usage, it is hard to tell whether a part worn tyre has hit kerbs, operated with the incorrect air pressure, or even if the tyre suffers from irreparable invisible damage.

This increased road usage is associated with a greater risk of blowouts and sudden tyre failures under stress, leading to a higher number of tyre-related collisions

Part Worn Tyres: False Economy

It can seem at first sight that a part-worn tyre is much more affordable. The fact that they are used products reflects this. 

However, over the long term, part worn tyres do not offer good value for money.

Given the fact that a part worn tyre comes with significantly less tread depth when compared with a new tyre, their lifespan is much less. Meaning a replacement tyre will be required much sooner. 

One way to look at the difference can be the cost per mm of a tyre.

At the point of purchase, a part-worn tyre can have as little as 2mm of the tread. The UK legal limit for a tyre is 1.6mm across 75% of the circumference of a tyre. 

So, with a 2mm part worn tyre, it would not be very long before another new set of tyres was required.

In addition, research has shown that part-worn tyres are often more susceptible to aquaplaning and provide reduced braking performance in wet conditions, increasing stopping distances and potentially causing more accidents.