UK Tyre Laws: What You Need to Know

Tyre Laws · Posted by: Mobile Tyres 2 U · 20th October 2020

When it comes to UK tyre laws, the key concern is tread depth. Tyre tread patterns are absolutely essential for allowing your vehicle to grip the road properly, particularly in inclement weather, so ensuring that your vehicle’s tyres are above the legal minimum in terms of tread depth should be your key focus.

What is the legal tyre tread depth?

Firstly, let’s take a look at the legal minimum tread depth for each type of vehicle.

• Cars, lorries, trailers and caravans: all of these types of vehicles must have tyres with a minimum tread depth of at least 1.6mm around the entire circumference of the tyre. This continuous band must take up at least the centre three quarters of the tyre tread.

• Motorcycles over 50cc: these motorcycles should have tyres with a minimum tread depth of 1.0mm around the entire circumference of the tyre. Like the vehicles above, this continuous band must take up at least the centre three quarters of the tyre tread.

• Mopeds and motorcycles under 50cc: For these sorts of vehicles, the original tread pattern of the tyres must merely be visible in order for them to be legally compliant.

How can I test tyre tread depth?

There are three key ways that you can test your tyres tread depth, these are as follows: 

• Perform a visual inspection: When performing a visual inspection, you want to look out for the tread wear indicators, these are small bars on the surface of the tyre that are around 5mm wide and built into the tread. If your tyre tread is level with the indicator, you are just over the legal minimum, but you should get your tyres replaced immediately.

• Tyre gauges: Tyre gauges come in a variety of different forms, from gadgets with digital displays to simple laminated cards, but they all work. To use, place the gauge into your tyre’s tread and you will be able to see how far above or below the minimum tread depth you are. We recommend using the gauge regularly and in different areas of your tyre to develop a full picture of your tyres’ overall health.

• The 20p test: If your tyres don’t have noticeable tread wear indicators, or if you don’t want to splash out on a new tyre gauge, there’s always the trusty 20p test. Given that the outer rim of a 20p coin is just under 3mm wide, when you insert one into your tyre’s tread, you should be able to glean one of two things: 1) if the outer rim of the coin is obscured, your tyres are comfortably above the legal minimum, or 2) if you can see part of the rim, then there’s a good chance your under the legal minimum.

When should I change my tyres?

While, legally, you don’t have to change your tyres until you’ve reached the legal minimum tread depth of 1.6mm, we would recommend changing your tyres before you reach it, just to be on the safe side. Around 2mm of tread depth is probably a good time to change your tyres, but if you’re approaching winter with a tread depth slightly higher than this, then it might be worth getting your tyres swapped out early.

What are the other legal requirements for my tyres?

Other than tread depth, there are two legal requirements that your tyres should fulfill:

• No defects: This simply means that your tyres shouldn’t have any obvious structural damage that may affect their performance, such as lumps, bumps and bulges. Cuts and tears larger than 25mm in length could also cause your tyres to be deemed defective.

• The right pressure: You should always make sure that your tyres are the right pressure but, unfortunately, this isn’t a one-size-fits-all scenario; each vehicle will have its own recommended tyre pressure value. To find it, try looking inside the driver’s side door, inside the petrol cap or, failing that, in the owner’s manual.

Are your tyres worn down and need replacing? Mobile Tyres 2 U are an experienced supplier and fitter of car tyres from the world’s most reliable tyre manufacturers. Serving customers in High Wycombe, Watford and the surrounding areas, we offer mobile tyre fitting and tyre replacement, including emergency replacements where and when you need it. We’ll fit your vehicle with brand new tyres and will recycle your old ones safely to protect the environment. We’re good like that.