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  • Writer's pictureMatthew Atkinson

How to Check Your Tyres are Safe (and Legal)

Don't leave your safety on the road to chance. In this guide we aim to demonstrate how to check your tyre is safe and the frequency in which you should do so.

The UK Legal Limit

In the UK the legal limit for tyre tread is 1.6mm. However, we do not advise you let your tyres wear down to this level and instead aim to change your tyres around the 2mm mark.

If you are pulled over and found to have tyres below the 1.6mm legal limit you could face a fine of up to £2,500 and 3 penalty points per tyre. So 4 illegal tyres could see you facing a driving ban and to accompany that £10,000 fine.


We advise that you check your tyres on a monthly basis or before any long journeys. This is to ensure both your safety, but also the safety of other motorists should you have a blowout.

As well as the checks identified below on the condition of your tyre, we also suggest you check the air pressure in your tyres on the monthly basis to ensure this is in line with your manufactures recommendations, reducing the risk of tyre failure and uneven wear.

Tread Depth

Many tyres now come with tread depth indicators. These indicators are small blocks of rubber between the treads which are precisely 1.6mm thick. Once the tyre tread is level with the indicator you know that the tyre tread has reached the legal limit and needs changing immediately. For tyres that don't have a tread depth indicator, the 20p test will work just fine.

The 20p Test

Using a 20p coin, insert it into the main tread groove. If the outer band is visible the tyre tread is below the legal limit and must be changed immediately. If the outer band sinks into the groove and isn't visible, the tyre is above the legal limit.

For more information we suggest you check out this video from TyreSafe demonstrating how to complete the 20p test on your tyres:

Tyre Aging

If do a low amount of miles in your vehicle the you may think your tyres are fine as they still have plenty of tread depth, however like all things in life, tyres have a shelf life and will deteriorate over time as the tyre ages. You will begin to notice cracking in the sidewalls as a result of the UV light aging your tyre, which increasing the risk of your tyre failing.

We suggest that regardless of their appearance, tyres should never see the 10 year mark on your vehicle due to the dangers this can pose on the roads. If you're struggling to identify the age of your tyres, there's a four digit code on the sidewall to let you know the week and year they were manufactured (i.e. if your code is 1010 then your tyre was manufactured in the 10th week of 2010).

Tyre Irregularities

As well checks on the tread and aging of your tyre, the final check should be for any irregularities in the tyre:

Bulges - If your tyres have any bulges in the sidewall your should look to change the tyre immediately as this greatly increases the risk of tyre failure or a blowout when travelling at high speed.

Punctures - If you have any sharp objects stuck in the tread or sidewall this could be a possible puncture which could result in tyre failure.

Cuts - Cuts can be caused by sharp objects such as glass, bad road conditions or damaged vehicle body parts which protrude in the direction of the tyre.

Irregular Wear - The tyres are wearing more in the centre or on the outer edges of the tread could point to an issue with the tyre pressure. High pressure can cause minimal contact between the tyre and the road, resulting in the centre of the tread wearing a lot quicker. Low pressure on the hand pushes the weight of vehicle onto the outer edges of the tread, resulting in outer tread wearing faster than the centre.

Think you may be due a tyre change? Give us a call for a no obligation quote. Best of all, if you decide to go with Grangetown Tyres for your next tyre change... We'll come to you!!

Blog article by Matt Atkinson, SME Geek Ltd


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