Search our site

RAC Duty of Care

UK Tyre Law & Tyre Care

UK Tyre Law

UK Law requires that your vehicle is fitted with the correct type and size of tyre required as recommended by the vehicle manufacturer. If you drive with damaged or worn tyres you could not only be fined and in breach of your motor insurance policy, but you could also be endangering lives.

What is the law relating to tyre tread depth?

To be in accordance with the law, tyres must have a minimum tread depth of 1.6mm in a continuous band around the centre three quarters of the tyre. This is the absolute minimum and tyres this worn should be replaced immediately.

To help you estimate how much tread you have left on your tyres, manufacturers normally mould tread wear indicators at 1.6mm. If these bars are visible your tyres are about to become illegal and unsafe.

Motorists found to have a tyre that falls below the 1.6mm minimum tread depth could face a £2,500 fine and three penalty points per tyre!

The first part of the law says there must be a minimum of 1.6mm of tread

The second part of the law says that the 1.6mm measurement must be across the central 3/4 of the tyre

The third part of the law says that the 1.6mm measurement must be all the way round the tyre

Tread wear indicators

These indicators are small raised areas at the bottom of the grooves of the tread pattern. If the surface of the rubber is level with these raised areas, the tyre has reached the legal limit of 1.6 mm and must be replaced. Beyond this limit, you are breaking the law. However, even if the remaining tread depth is greater than 1.6 mm, drivers should adapt their speed and driving style to the external conditions, particularly on wet roads. For these reasons, a user might be inclined to replace their tyres before the legal limit, if they estimate that the performances of the tyres are no longer in accordance with their usage.

RAC Duty of Care strongly recommends that you consider changing your tyres before this limit is reached. On a wet road, the use of worn tyres increases the risk of losing control through aquaplaning. On tyres that are too worn, the tread patterns do not displace the water collecting under the tyres, leading to loss of control of your car. It is universally recognised in the tyre industry that the legal limit is wholly insufficient to protect drivers in adverse driving conditions. Drivers are therefore recommended to consider replacing their tyres when the tread depth reaches 3mm.

Tyre care

Maintaining correct tyre pressures

There are three main reasons why maintaining the right tyre pressure is important.

Safety
Tyres that are under inflated can overheat; and over inflated tyres can lead to poor vehicle handling on the road.
Economy
Over or under inflated tyres suffer more damage than those with the correct pressure and need to be replaced more regularly. Vehicles with under-inflated tyres have increased rolling resistance that require more fuel to maintain the same speed.
The environment
Correct tyre pressures help to maintain optimum fuel efficiency. This can equate to lower CO² emissions coming from your vehicle than those with incorrect tyre pressures and that has to be good for the environment.

At least every week check the tyre pressure (including spare) and before any long trip. Incorrect tyre pressure may adversely affect tyre life and vehicle handling. Correct the tyre pressures if they no longer correspond to the pressures recommended by the vehicle manufacturer. Tyre pressure should be checked when tyres are cold after the vehicle has been parked for three or more hours, or driven less than 1 mile. Insufficient pressure can lead to overheating of the tyre and subsequently internal damage. At high speeds, this could result in tread separation and even bursting of the tyre.

Tyre inspections