HGV tyres follow different legal tread depth rules compared to standard vehicles, and understanding these limits is essential for safety and compliance. This guide explains the 1mm legal requirement, how to measure tread depth accurately, and why heavy goods vehicles need less tread to maintain grip. Stay informed and ensure your HGV is roadworthy before every journey.
With so many moving parts on an HGV, it’s important that any vehicle maintenance you undertake covers the legal limits as well as various elements of road safety.
Tyres remain one of the most critical features to inspect and monitor as part of your vehicle maintenance, regardless of whether it’s an HGV or a small runaround car. But while tyre tread, inflation, and size are all important things to check on vehicles of all shapes and sizes, one crucial thing that differs is the minimum tyre tread depth.
Interpreting Tyre Tread Depth on an HGV
The minimum legal tread depth for HGV tyres is 1mm.
This is much smaller than the legal limit for a standard vehicle, which is 1.6mm.
The reason for this difference in tread depth is the weight of the vehicle and the amount of friction it holds atop the road surface as a result of its weight. An HGV is, by its definition, an extremely heavy vehicle which makes it easier to control on even a wet or slippery road surface. Because tyre tread depth is directly related to grip on the road, it follows that an HGV requires less in the way of tread in order to offer the same stability and support.
How to Measure Tread Depth on an HGV
Most vehicle owners are familiar with the 20p coin trick for checking tread depth on a tyre requiring at least 1.6mm. But what about an HGV that needs only 1mm of tread across the majority of the tyre surface?
It is recommended by the UK government that HGV drivers check their tyres with a blunt probe, taking care not to damage the tyre surface with a sharp object.
As part of a tyre inspection, the pattern of the tread should also be taken into consideration, to ensure that any wear across the tyre surface is even. The minimum tread depth of 1mm must cover at least 75% of the tyre surface, while the remaining 25% should at least show the outline of the original tread pattern. If the pattern has completely worn away from the tyre surface, you can conclude that the wear is uneven and therefore unsafe.
