A Guide To Trailer Tyres

Do you need special tyres for a trailer?

Wondering what type of tyre is best for a trailer? While trailer tyres might look like regular vehicle ones, they have different characteristics to handle being towed and carrying weight. Here are the main differences between car and trailer tyres:

• Sidewalls. Trailer tyre sidewalls are stiffer to accommodate carrying heavier loads than car tyres and avoid swaying.
• Load capacity. Trailer tyres are designed to support far larger weights.
• Tyre markings. Trailer tyres will often be marked with an “ST” indicating “Special Trailer” tyre.

Can I put regular tyres on a trailer?

Regular tyres and trailer tyres are not interchangeable on account of their different uses and characteristics. Swapping in regular car tyres for trailer tyres could lead to both the tyres wearing down far quicker, and to dangerous situations like your trailer swaying, the tyres failing, or even accidents. 

Find trailer tyres at Kwik Fit

What is the law on trailer tyres in the UK?

We’ve seen plenty of drivers come into our centres with a trailer with tyres so worn that the cords were showing. You wouldn’t let your car tyres get into this sort of state (well, we certainly hope you wouldn’t), and yet many drivers seem to think there are no restrictions on the condition of tyres when fitted to a trailer. In actual fact, the same laws apply to trailer tyres as regular car tyres:

• Cars and light trailers up to 3,500kgs must have a minimum tread depth of 1.6mm across the centre three-quarters of the tyre and around the entire circumference. 
• Your trailer tyres should be free of cuts and bulges, and mud guards must be fitted and secure. 
• It is illegal to use a mix of tyre types (EG: to have cross-ply and radial tyres on the same axle).
• You should make sure that the trailer tyres you choose are of the correct rating.

If the police were to pull you over and found your tyres to be substandard, you could face the same penalty as car tyres: that is, 3 penalty points and a maximum fine of £2,500.

The National Trailer and Tyre Association has even more details on tyre and towing rules if you want to find out more.

How often should trailer tyres be changed?

If your trailer tyres get damaged, reach a certain age, or begin to show signs of wear, they should be changed, or at the very least brought into a garage to be inspected by an expert. 

It might be time to change your trailer tyres if…

• You can see scuffs and tears on the tyre sidewalls and tread area.
• There’s damage to your tyres (EG: bulging, cracks, or punctures).
• Your tread depth is less than the legal minimum of 1.6mm (Learn how to measure this with our handy 20p trick in another blog). If you frequently drive in wet conditions, it's recommended to replace your trailer tyres earlier, around 3mm.
• Your tyres are older than 6 years old.

Do trailer tyres go bad from sitting?

Yes, trailer tyres can “go bad” from inactivity or being left sitting on your driveway. Rubber is a natural material and can degrade over time. If exposed to the elements, your trailer tyres may encounter something known as “dry rot”, where they become harder and more prone to cracking. 

Being exposed to sunlight, poor weather, and extreme temperatures can cause reduced tyre lifespans due to things like UV damage and flat spots (this is where tyres get flatter in pressure points if they are not rotated regularly). 

How do you tell if you need new trailer tyres?

Keeping a close eye on the condition of your trailer tyres is essential to avoid unexpected damage, and to extend their lifespan. 

Check your trailer tyre pressure

All tyres lose pressure over time whether in use or not, so it’s important to check the tyre pressure on your trailer tyres before you take it out for the first time in a while. 

• Flat or low pressure tyres on a trailer are not immediately obvious if the trailer is unloaded, as the tyres may still have enough air to support their own weight, so check your tyre pressure every time you get the trailer out. 
• Even if your trailer is in regular use, you should check your tyre pressure every few weeks and correct when needed. 

Under inflated trailer tyres will wear much faster and unevenly if not addressed, especially if you are transporting heavy loads.

Inspect your trailer tyres for damage & ageing

Another consequence of tyres being in storage for a long time is that they are prone to cracking. Tyres are constructed with a wax in the veneer; this acts as a sort of moisturiser which helps to keep the tyre supple. 

• If a tyre is not in regular use, the wax will slowly seep to the bottom of the tyre which can lead to cracking as the tyre dries out. 
• If the trailer is left outside in the elements, UV light from the sun will slowly oxidise the rubber in the tyres, which can also lead to premature tyre ageing.

Give your trailer tyres a thorough visual inspection before you take the trailer out. Also,  check the date of manufacture on the tyre sidewall, as trailer tyres are more likely to be unchanged for several years due to their occasional use. 

Find out the age of your tyres

Buy trailer tyres at Kwik Fit

At Kwik Fit, we stock a wide range of trailer tyres for different trailer types. Our centres may not have your specific trailer tyre available on the shelf, so we recommend contacting your nearest centre beforehand to let them know your requirements and tyre size. 

Our team can then order the most suitable tyres for your trailer from our warehouse for fitting at a time that is convenient for you. Contact your local Kwik Fit today.