Tyre Safety: Tread depths and staying legal
22 April 2020
/ Andrew Burgess
Checking the tread depth of your tyres is one of the most important checks you should be making on a regular basis.
Having worn tyres means that the one thing in contact with the road surface is not able to perform as it should. This has an impact braking distances and handling, which could be an accident waiting to happen.
If safety isn’t enough to make you think about checking, having worn tyres can also hit you in the pocket. If the police find your tyres to be below the legal tread depth, you can be fined up to £2500 and receive 3 penalty points – PER TYRE. That means you could potentially lose your license and have a maximum of £10,000 fine, if all of your tyres are illegal. You can prevent this just by checking your tyres.
The legal tyre tread depth
The legal minimum tread depth for cars 1.6mm across the central three-quarters of the tread and must meet this minimum requirement around the complete circumference of the tyre.
The recommended tyre tread depth
Tyre and safety experts believe the 1.6mm legal minimum is not sufficient to maintain safe braking distances – most recommend a minimum tread depth of 3mm for tyre replacement. The legal limit for tyres in Germany is 3mm, which is where a lot of part worn tyres come from.
The tread on a tyre helps to disperse water in the wet, preventing aquaplaning, helping to maintain contact with the road’s surface. The difference in wet braking distance between a tyre worn to 3mm and one worn to 1.6mm can be as much as 44%. So, bare that in mind when considering buying part worn tyres.
To give you an idea of how important the tread is to the performance of the tyre, in heavy rain, each tyre can shift one gallon of water every second. Essentially, deeper tread means better grip.
Checking your tyres
You should check each of your tyres at least once a month and ensure that your spare tyre, if you have one, also has a legal tread depth. There are there are three ways to do check:
There are three ways to check this:
The 20p test
The 20p test is an easy and quick way to check that your tyres are within the legal tread depth limit. All you need is a 20p coin. Insert the coin into the tread grooves on the tyre. If you can't see the band that runs around the edge of the coin, your tyres are above the legal limit.
If any of the band is still visible above the rubber tread, your tyres could be unsafe, give us a call or drop in and we will check them for free to make sure you are safe and legal.
Tyre tread depth gauge
Tyre tread gauges are small devices that quickly and accurately measure the depth of your tyres. Basic gauges are available from Amazon for around £5 and are the easiest way to get an accurate reading of your tyre tread depth.
If you want someone to show you how to check or want a second opinion, give us a call or drop in and we will show you and check your tyres for free to make sure you are safe and legal.
Tyre tread wear indicator blocks
All tyres have tread level indicator blocks within the tread. These indicate the minimum legal tread depth. If the tread gets to this level, your tyres will be on the legal limit and performing far below their best, meaning you may be having to deal with increased braking distances and your car’s handling could be impacted.
If you are not sure how to check or want a second opinion, give us a call or drop in and we will check them for free to make sure you are safe and legal.
Part worn tyres may look like a cheaper alternative but it is worth considering why these tyres are available and what the cost is.
Generally, these tyres are imported other countries in Europe, including, German where the minimum legal tread depth limit is 3mm. 3mm is the limit that a most tyre safety experts consider to be a safe tread depth. So, while these tyres may be legal, they may not perform as well as you might expect and certainly will not perform as effectively as new tyres with a deeper tread.
You can never be sure how old part worn tyres are or where they came from. Rubber degrades when exposed to the elements and can crack which will result in less grip as time goes on. New tyres have never been on a car or driven so you can be sure that you expect the performance that the tyre manufacturer intended.
The cost of part worn tyres may look more appealing, but they are generally sold with around 3mm of tread, compared with around 8mm when the tyres are new. That means that you will get around 1.4mm of legal tread to use, although the tyre will not perform as well as a new tyre. Research by Partworn-tyres.co.uk estimates the cost of part worn tyres to be approximately £6.33 per mm of tread. While the cost of equivalent new tyres is estimated to be £5.32. So, while the cost may look cheaper initially, in the long run new tyres will perform better and could work out much cheaper.
We only supply new tyres, so if you want the safest and most economical option, give us a call or drop in, we will be happy to help you and ensure you get on your way with legal and safe tyres.
If in doubt, let us check it out
If you are at all unsure about how to check your tyres give us a call or pop in and we will show you how to do it. We are here to help and to make sure you stay legal and, more importantly, safe on the road.