Car Tyres and the Law.06 June 2019
Do you know the law on car tyres?
The tyres of your car are the only part of the vehicle that comes into contact with the road, so it is vitally important they are maintained and kept in good condition. There are a number of specific legal requirements related to the conditions of your tyres. Below we go into more detail about the law and what you need to look out for.
UK legal tyre tread depth
The tyre tread depth plays a key role in maintaining the safety of both the car and the driver. By law, it should never be any less than 1.6mm across the central three-quarters of the entire circumference of the tyre.
There have been many studies carried out to understand the effects of the tyre tread on a car’s stopping distance. These have confirmed that a tyre tread of 1.6mm increased its stopping distance by almost 37% on hot rolled asphalt (used to build roads) and by over 44% on smooth concrete. Other studies have even shown that tyres with a lower tread than 3mm should be replaced, as they will deteriorate faster and anything beyond this point will negatively impact on braking distances.
Would your tyres pass an MOT?
By law, any car over three years old needs an annual MOT to ensure it is still fit to drive. This also includes checking your tyres are in good condition. Here are the main issues to regularly watch out for to avoid your tyres failing an MOT.
You should check the air pressure in your tyres once a week. They bear the brunt of the road and weather conditions, as well as the entire weight of the vehicle every day. Refer to your vehicle’s manual which will tell you what the level of pressure each tyre should be.
Depending on the weight being carried by the car, the required pressure may differ. When your tyres are not at the correct pressure, not only could you have less control over the steering, but also on its braking capabilities. If you are unable to check the tyres each week, you should ensure it is done monthly at the very least, or to the conditions of the load you’re carrying.
Tyre mixing relates to an important part of the car’s setup that should always be paid attention to. This means it should have the same tyres on the front two wheels and the same two on the back.
Mismatched tyres can adversely affect your stability, steering and speed, plus can cause vehicle damage in the long term.
Modern cars are supplied with radial-ply tyres instead of cross-ply, but the two should never be used on the same axle. Each tyre type has its own strengths and weaknesses, so it is illegal to mix cross-ply and radial-ply tyres on the same axles.
In addition, tyre manufacturers use their own unique compound mix, so you should always purchase tyres from the same manufacturer.
Just as you should keep a close eye on the tyre pressure, you should also check for any defects that may appear. If you spot any bulges, tears, cuts or anything that has become embedded in the tyre (nails, screws or glass for example), you should arrange to have it replaced as soon as possible.
Ignoring it will only make driving the car more dangerous each time the tyre takes to the road, as you never know if it might fail at any moment. Although, UK law does state that any cut covering less than 25% of the tyre section width, or is smaller than 25mm, is still legally acceptable.
When you take up a maintenance package with Leasing Options, you may not have to pay for replacements for your premium tyres. Our Total Care insurance package also includes this as standard, so if your tyres are damaged and have not been neglected, abused, vandalised or stolen, we can replace them for free, saving you money that can be used elsewhere.
By law, you are not required to have a spare tyre in the boot of the car, although it is recommended that you have one to hand, just in case. If you do have a spare tyre, safety checks will also have to be carried out on it. Again, this is not a legal requirement, but in the unexpected event you need to use the spare tyre, you want to be sure it is safe and up to the required standard.
Remember that spare tyre laws may be different if you are driving to another country, so always check this before you depart. When you are leasing the car, ask if it comes with a spare tyre included. Some manufacturers provide a tyre repair kit to save on space, while others supply a skinny spare wheel that is intended for use only in an emergency. These types of tyres can only be driven at a maximum speed of 50mph, so bear that in mind if you have to use them.
How to check your tyres are roadworthy
An MOT should be carried out annually for cars over three years old, but to stay safe in between tests, here are some checks you can perform yourself.
Check your tyre tread
As we mentioned above, your tyre tread depths must legally be at least 1.6mm. This should be in the middle three-quarters of the tyre around its entire circumference.
There are two ways you can check this. Firstly, use the tyre tread wear indicators which are found across the whole tread. If the tyre is flush with these, it could be that it is below the minimum 1.6mm level.
Secondly, you can use a 20p piece to double check, as the border of the coin is approximately 1.6mm. Place it into the tread grooves on the tyre, and if you can still see the border of the coin, the tyre should be replaced.
When the car is being driven, the tyre sidewalls are under sustained pressure. Any damage to these could potentially lead to a blowout. This could put you and others in real danger, which is why they should also be checked frequently.
You can inspect the outside walls visually – if you spot a little cracking, this is usually nothing more than wear and tear due to the age of the tyre. Anything else should be checked by a trained mechanic. When a tyre wall is damaged it will usually have to be replaced, as in most cases they cannot be repaired.
Take a look at the tyres for any nicks, cuts or tears. Not only can these develop into larger holes over time, but water can seep inside, which can ruin the effectiveness of the tyre. Also, keep an eye on the tyre pressure to ensure they are in line with the manufacturer’s recommendation, which can be found in the car manual.
At Leasing Options, our maintenance package covers all routine work, including premium tyres, so you do not need to worry about replacing yours. You can read more in our FAQs, or contact our team for additional information.