Advice & Guidance on Tyre Tread and UK Tyre Law
UK Tyre Law : Tyre tread and the Law
The law requires car tyres to have a minimum tread depth of 1.6mm in a continuous band around the central three quarters of the tyre. To help you judge how much tread you have on your car tyres, manufacturers often mould tread bars at roughly 1.6mm.
If you can see these bars your tyres are about to become illegal and unsafe. However, for optimum safety, most manufacturers recommend that your tyres are changed at 3mm.
Many manufacturers now include a Tread Wear Indicator (TWI) within the grooves of the tyre tread which become more visible as the tyre wears down. Whilst these markings are an indicator, always check the tread depth using a tread depth gauge and check your tyres regularly for bulges or wear.
The writing on your tyres can be confusing. The sidewall of typical tyre is imprinted with myriad codes and numbers that are used to identify the size and physical features of that tyre as well as details relating to its manufacture. Many of these tyre markings are of little or no importance to the driver while others are essential when it comes to choosing a replacement tyre.
If you are looking for new tyres you should familiarise yourself with the following tyre markings:
The load index provides information on the maximum weight capability for the tyre. The load index is a numerical code that can be located just after the tyre size marking and before the speed rating.
Although not illegal, it is not advisable to have tyres with a lower speed rating or load index than the manufacturer recommended tyre specification for your vehicle, or to have a combination of different tyre construction types. Consult your vehicle handbook to confirm your vehicle’s tyre speed rating and load index as well as any additional requirements.
Date of Manufacture
Tyres with an increased load index are often marked to show that they have been reinforced to handle extra weight. This varies from one manufacturer to the next but look out for the following symbols which are used to identify if the tyre has been reinforced.
Run flat tyres are specially designed with strengthened side walls so that, in the event of a loss of pressure such as a puncture, the tyre can hold the weight of the vehicle and continue to be used for a short time until you can reach an appropriate place to stop and have the tyre replaced. There are many different tyre markings for run flat tyres depending on the manufacturer.
Switching to run flat tyres
If your vehicle is fitted with conventional tyres and was not fitted with run flat tyres at time of manufacture, we would advise against fitting run flat tyres to your vehicle. All vehicles fitted with run flat tyres require a tyre pressure monitoring system (TPMS) which alerts the driver should the tyre receive a puncture or there is a sudden drop in tyre pressure. Without TPMS, fitting run flat tyres could be a major safety risk as the motorist could continue driving, unaware there is an issue with the tyre.
Similarly, you should avoid fitting conventional tyres to a vehicle set up for run flat tyres. Most vehicle manufacturers who fit run flat tyres as standard no longer provide a spare tyre or tools to change your tyre. Therefore, if you switch back to conventional tyres, you may not have the means to replace the tyre on the side of the road should a puncture occur.
Can run flat tyres be repaired?
Unfortunately, when a run flat tyre picks up a puncture it’s hard to tell if the structure of the tyre wall has been compromised because the punctured tyre could have been driven on for an excessive amount of time or at unsuitable speeds (over 30mph). For this reason, we cannot repair run flat tyres as they as may have weakened and no longer be safe to use.
If your run flat tyre receives a puncture, we would advise the tyre be replaced as soon as possibleto. Give us a call asap to see if we can either replace it for your or reccomend another tyre centre and having .
What are the best run flat tyres?
Run flat tyres are produced by a number of tyre manufacturers including budget and premium brands. However, as with regular tyres, we would recommend that the best run flat tyres are those produced by premium manufacturers and tyre names you are familiar with. Tyre brands like Pirelli, Continental, Goodyear and Michelin invest a great deal of time and resource in the research and development of new run flat tyres to ensure their run flat tyre products offer maximum safety that never compromises performance or control.
At Everest Motors we stock a range of tyres from premium manufacturers.