There's no legal time limit stating when tyres need to be changed. The lifespan of a tyre depends on a number of factors, including the driver's habits (e.g. driving style), the condition of the road, the climate and how well it's looked after.

The more miles you cover, the quicker your tyres will need to be changed; however, on average, you can expect a tyre to last between 20,000 - 30,000 miles. Although there's no set time for when you should replace your tyres, most manufacturers agree that tyres shouldn't be used for longer than 10 years after the manufacturing date.

Even if a 10 year old tyre is within the legal tread depth regulations and doesn't show any visible signs of ageing, there could be internal damage comprimising its safety. To check the age of your tyres, you need to find the DOT code on the sidewall.

The date a tyre was made will be stamped on one side in the form of four numbers usually preceded by the letters 'DOT'. These numbers represent the week number and the year. For example, if your tyre was printed with the number 2616, it would be the 26th week of 2016.

Once your tyres get to five years old, it's recommended to have them checked by a tyre professional every year to ensure they're still in good condition and safe to use.

When Do I Need To Change My Tyres?

If your tyres are under ten years old, there are three occasions when they need to be changed:

  1. When you have a puncture
  2. When the tread depth is below the legal limit
  3. When the tyre is visibly damaged

WHEN YOU HAVE A PUNCTURE

Punctures are the most serious form of tyre damage and should be dealt with immediately. There are two different types of puncture that a tyre can experience: fast and slow.

Fast punctures, also known as blowouts, occur when the tyre bursts (by driving over a pothole at speed, for example) causing it to instantly deflate. A car with a burst tyre is not safe to drive. If this happens, you should pull over and put the spare tyre on; if you don't have a spare tyre, call your breakdown cover to take you to the nearest tyre shop to fit a replacement. 

A slow puncture occurs when a small breach in the tyre - which could be caused by a piece of debris stuck in the wall - leads to a gradual leak of air. Many drivers continue to use a car with a slow puncture for a considerable time before getting the damaged tyre changed. This is not advisable. A slow punctured tyre will increase your probability of being involved in a road accident and should be changed as soon as you notice it.

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WHEN THE TREAD DEPTH IS BELOW THE LEGAL LIMIT

Tread is the rubber on the outer surface of the tyre which has grooves to help it grip the road's surface. The depth of the grooves is known as the tread depth. In the UK, the legal tread depth limit is 1.6mm.

There's a simple way to check whether your tread depth is within the legal limit called the 20p test. Take a 20p coin and put it into one of the tyre's grooves. If the outer ring of the coin's design is covered by the tread, then the tread is safe. However, if the coin's outer ring is not covered, then the tread is not deep enough and is illegal - you should replace that tyre immediately.


WHEN THE TYRE IS VISIBLY DAMAGED

Ideally, before you start a journey, you should take note of the state of your tyres to see if there are any obvious bulges, blisters or splits in the sidewall. The appearance of any of these indicates serious internal tyre damage. 

Also make sure to check your tyres for 'blistering'. This is where excessive heat causes chunks of the rubber to sheer off and could lead to a puncture while you're driving.

While you're checking the condition of the sidewalls, you should also look out for uneven patterns of wear which can result from misaligned wheels, incorrect tyre pressure or excessive turning. Uneven wear doesn't necessarily mean that you need to change the tyre immediately, but it will alter your steering and may also lengthen your braking distance. 

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What Affects The Wear & Tear Of Tyres?

Being able to spot the signs of tyre wear and tear will make it easier to know when your tyres are likely to need changing before they blowout, get below the legal tread limit or become damaged. There are many factors that can affect how quickly your tyres will need to be changed.

DRIVER'S HABITS

Your own driving style is the easiest factor to control. Consistently driving fast will wear the tread more quickly, as will aggressive braking, accelerating and cornering.

Similarly, the number of miles you cover every year will affect a tyre's longevity. Tyres that travel 3,000 miles a year will inevitably last longer than tyres that complete 15,000 miles every 12 months.

ROAD CONDITIONS

Driving on a smooth, freshly tarmacked road is obviously going to be more beneficial to your tyres compared to a gravel road.

In addition, a lot of city driving will increase the chances of encountering speed bumps or having to drive on a road littered with potholes. 

CLIMATE

Extreme weather conditions accelerate tyre damage; soaring temperatures will heat the road up and could lead to cracks, whereas wet weather can directly wear the tread away.

If you have a garage or enclosed parking space, this will help to increase the lifespan of your tyres.

TYRE PRESSURE

Manufacturers always specify the correct pressure for a tyre - normally you can find them in the car's manual, inside the petrol cap or printed on the inside ledge of the driver's door.

Tyres that are at a significantly lower pressure than their optimal rate will wear more quickly because they will flatten and more of the rubber will be in contact with the road, causing an increased amount of friction.

The most common cause for a tyre blowout is underinflation. The increased friction from the flatter tyre generates heat which weakens the tyre and eventually leads to it bursting.

Tips For Buying Replacement Tyres

When you inevitably need to buy new tyres, there are a few tips to get the best results:

  • Try to replace all four at once - even though this will be expensive, getting a full set of new tyres will provide optimum handling and control
  • Always replace tyres on the same axle at the same time - whether it's the front or rear, you should replace both of them to retain wheel alignment and ensure an even wear
  • Match them with the old tyres - try to get the same brand, load capacity and tread pattern as the ones you're replacing
  • Keep the same speed rating - especially if you're not replacing all four at once, otherwise some of your tyres will be capable of higher speeds than others

Your tyres are the only part of the car that comes into contact with the road, so it's crucially important to keep your tyres in the best possible condition to improve your safety and the safety of other road users.