Ever wondered what really happens when your tyres wear out? This guide explains how worn tyres affect safety, control, and performance — plus how to measure tread depth, recognise early signs of wear, and prevent costly damage. Learn how regular checks and timely replacements keep you and your car safe on the road.
The more you use and drive on your tyres, the more worn out they get.
Of course, wear and tear is to be expected and is a part of driving that impacts virtually all vehicle components. However, there comes a time in the lifespan of a tyre when the level of wear becomes destabilising and unsafe.
In this article, we’re looking at what happens as a tyre becomes more worn out, and why this impacts the safety of driving.
What Causes a Tyre to Become Worn?
When we consider tyre wear, we are usually talking about the tread around the outer edge of the tyre. As this is the part of the tyre that makes constant moving contact with the road, it becomes increasingly worn every time you drive the vehicle.
To make tyre tread wear easy to monitor, there exists an industry standard – a minimum tyre tread depth that all tyres must meet in order to be considered legal. This is 1.6mm, measured from the base of the tyre tread grooves to the upper ridge of the tread pattern.
It’s important to note that, because tyre wear affects the outer edge of the tyre, driving style and behaviours have a huge impact on how quickly your tyres become worn. Driving on rough surfaces exacerbates the rate of wear. If wheels are not aligned, this can also cause wear across the tyres which may be uneven, while having tyres that are unsuitable for the environment can increase the risk of damage.
How Do I Know if My Tyre is Worn?
The easiest way to determine if a tyre is worn out, is to measure the tread depth at different points across the full width of the tyre.
If the level is different at different points, then you know the rate of wear is unbalanced and that there could be an issue with tyre alignment. If the tyre depth reading falls below the 1.6mm minimum, then tyres are classed as worn out and need to be replaced.
The best way to measure tyre tread depth is with the 20p coin trick, by reading the tread markers, or by using a professional tread depth gage.
So, that’s how to spot worn out tyres – but why is this important, and what makes excessively worn tyres so problematic?
Why Do Worn Tyres Need to be Replaced?
As tyres become more worn, it is important to increase your rate of inspection, and the number of maintenance checks you carry out.
This is because as the tyre tread becomes more worn, tyres are at higher risk of damage – and there is a higher risk of you losing control as a result of a tyre blowout or skidding. The tread around the outside of the tyre facilitates grip and traction and plays an integral role in protecting the vehicle from the impact of potholes and other debris.
As part of your regular checks and inspections, you should also focus on the sidewall of the tyre. Any damage here can instantly result in the tyre being written off, as it hides potentially destabilising damage to the tyre’s structure.
