How to ... Check Your Tyre Tread Depth
What is Tyre Tread?
The tread of a tyre is the pattern of grooves and ridges over the rubber surface. The tyre tread depth is how deep each of these grooves is, new tyres will start life with a tyre tread depth of around 8mm. As you drive around the rubber surface of your tyre gets worn down making grip on the road less effective.
The tyres are the only place where your car makes contact with the road, so it is vital these are in tip top condition. You need to check the depth of your tyre tread regularly, ideally every 2 weeks, to ensure you are safe on the road and here's how ...
How to check your tyre tread depth
You will need;
- A tyre depth gauge or
- A 20p
Step 1 : Insert the tyre depth gauge or 20p into grooves on your tyre.
Step 2 : Look at depth measured.
If using a tyre depth gauge, remove and read the scale.
If using a 20p ensure the outer band is entirely covered by the tyre once in the groove.
Your depth needs to read 1.6mm or above to be legal.
Step 3 : Take several readings
To be legal your tyre needs to have a tread depth across the central three-quarters of the tyre, so make sure you take several readings across the width of the tyre.
What does tyre tread do?
The purpose of tyre tread is to provide as much grip to the road surface as possible. One of the most important jobs tyre tread does is to channel water from the road surface away from the tyre to maintain contact with the road and reduce the risk of aquaplaning. If a tyre is in good condition it is capable of moving around 15 litres of water a second, this amount reduces the more worn a tyre becomes.
What is the legal tyre tread limit? : Tyre tread law
For your tyres to be legal the tyre tread depth must be at least 1.6mm across the central three-quarters of the tyre.
However, most professionals will recommend you change your tyres once the depth tread reaches 3mm. This is because tyre performance reduces significantly at this point. When tyres are tested in the wet, a tyre of 1.6mm will have a stopping distance around 44% longer than a tyre with 3mm of tread.
What happens if my tyres are below 1.6mm
If your tyres are below 1.6mm you must immediately get them replaced. In addition to the safety issues worn tyres raise, you risk a £2,500 fine and 3 penalty points on your licence per tyre.
If you are in an accident and your tyres are found to be worn below the legal limit of 1.6mm, it is likely your insurance policy will be invalid. This means you will have to find the money to pay for any necessary repairs yourself.
If you are not confident that you can check your tyre tread depth accurately yourself, make sure you ask a trained professional.
Leave a comment for your chance to win £20 of High Street Vouchers. Each month Natalie picks her favourite comment from the previous month - get involved for your chance to win...
The comments above do not necessarily reflect Rivervale's views unless clearly stated.
23 April 2018
Written by Natalie Faughy