Summer tyre change: a simple guide to measuring tread depth
The days are getting longer and temperatures are rising – which means the time has come to fit your vehicle with summer tyres.
To determine whether you need new summer tyres or not, you should first see if the old ones have the legally required minimum tread depth. Tyres with a worn tread do not provide sufficient road grip and pose a risk in traffic situations. For that reason, you should check your tread depth regularly and not just during the seasonal change.
Especially on wet surfaces, braking distances are significantly longer with worn-down treads.
Key tread depth measurements
Tyres fresh from the factory have a tread depth of around 8–9 mm, and the minimum tread depth under current legislation is 1.6 mm. For summer tyres, we recommend a remaining tread depth of at least 3 mm for your safety. The ability of tyres to grip the road decreases significantly when the tread depth is less than 4 mm, especially in wet conditions.
What is the correct way to measure tread depth?
- Some tyres feature a tread wear indicator (TWI). Take a look at the small bars inside the tread grooves all around your tyres. If these are flush with the outer tread, the tyre is already worn and it is high time to replace it. However, these small bars only allow you to determine whether the tread meets the legal minimum requirement. Tyres at this stage will have already worn below our recommended tread depth of 3 mm. It is therefore better to use a more accurate measuring method.
- Different tread depth gauges are available that can provide exact measurements. These include laminated cards with colour-coded markers and vernier gauges. Such tools can be simply inserted into the tread groove to provide an accurate reading of the remaining tread depth of your tyres.
- The coin trick: for a quick measurement without any tools, you can position a 20 pence coin between the tread grooves. If you can’t see the outer band of the coin the minimum tread depth has not yet been reached, but if you can you need to get the tyre inspected as soon as possible.
- If you are unsure about how to measure tread depth, ask your tyre dealer for advice.
Is the tread depth of your tyres too low? Our recommendation to keep you safe on the road, even in the rain:
Click on one of the tyres to see more information about the product and find the right tyre size for your vehicle.