Tyres are probably one of the most overlooked parts of any car. But they’re also one of the most important – literally where the rubber hits the road. We explain how to choose them, check them, and if necessary, change them.
Why are tyres important?
Your tyres’ only direct connection with the road (known as the contact patch) is about the same size as the palm of your hand, but nevertheless, they’re the only thing connecting your car to the road. They grip the road, enabling the car to steer, accelerate and brake, and also help to smooth out any bumps in the road surface.
Your car relies on its tyres, so it’s a good idea to treat them with the importance they deserve.
How to check your tyre pressure
Checking tyre pressures regularly is a simple way to care for your tyres.
Tyre pressure is important. Under-inflated tyres can overheat. Overinflated tyres affect the car’s handling, for example making it harder to corner, and stop.
Incorrect pressures can also lead to tyres wearing more, and wear unevenly, so they’ll need to be replaced more often (which is an unnecessary expense for you). Under-inflated tyres also result in more fuel being used up to move the car, which is inefficient and means more CO2 is being produced, so you're causing more damage to the environment than necessary.
We’d recommend checking your tyre pressures with a tyre pressure gauge every couple of weeks, to be safe: your tyres need to be cold when you do so. Your car might have a tyre pressure monitoring system, which can tell you the pressure of each tyre and warns you if any of them get dangerously low. It's still worth physically checking them every so often, though, just as a back-up.
Your car’s correct tyre pressures – and cars usually have different recommended pressures for the front and rear tyres – can be found in the handbook, as well as on a sticker located in one the frames of the front doors, or inside your fuel cap.
Tyre tread depth
Tread depth is the measure of your tyres’ deepest grooves. The amount of tread on your tyres is important for safety as it helps them grip the road, especially in wet conditions.
The legal minimum tread depth in the UK is 1.6mm, measured in the middle three-quarters of the tyre’s width and all the way around. Each tyre failing to meet this standard could mean three penalty points on your licence and a £2,500 fine.
Checking is easy: do it when you check your tyre pressures. You can use a proper tread depth indicator but it’s simpler to use a 20p coin. Place the coin inside the main tread groove of the tyre and if you can’t see the outer band of the 20p piece, there’s enough tread: if you can see the outer band, it’s time for a change. Repeat this process at three different places, to make sure that the tread wear is even across the whole tyre.
How to spot tyre damage
Tyres can also become damaged by rubbing or pinching when parking next to a kerb, or driving over a pothole. The rubber in the tyre’s sidewall can have cracks, bulges or blisters, which are a sign of serious damage that could lead to a blowout. If you spot something like this on a regular check, replace the tyre as soon as possible.
What are run flat tyres?
Run flat tyres are specially designed to remain usable (at a limited speed) even after a puncture. They have a harder, self-supporting construction, so they’re more robust – but they’re not totally indestructible.
Only certain car models that are designed to be fitted with run flats can use them. Every tyre brand uses different symbols to mark their run flat tyres. The only way to know if your car has them would be to consult your manufacturer’s handbook or ask a tyre consultant.
What are winter tyres
Winter tyres or cold weather tyres use a different type of softer rubber than regular tyres and have a tread pattern that includes grooves known as ‘sipes’ that help disperse snow and water. They allow a car to brake faster than one with regular tyres, reducing the stopping distance and making them much safer to use.
Do we need winter tyres in Britain? Possibly not in the southern parts of the country, especially if we’re going to continue having milder winters, but if you live in hilly parts of the country, or in the north, they might be a good investment, as you’ll be able to drive normally when other cars with regular tyres struggle.
Changing your tyres
You must change tyres before the tread gets to 1.6mm, with many organisations suggesting that you make the switch at 3mm. However, a good-quality tyre will continue to be effective down to 1.6mm, so throwing away tyres before that is a waste of money and just adds to landfill.
But if you do have to change tyres, try to buy them in pairs, or as a complete set of four. You don’t have to stick with the type of tyre that was originally fitted by the manufacturer, but the two front tyres or two rear tyres should match (same brand, tread pattern, dimensions and ratings), because then you know they will perform identically.
If buying in pairs rather than a complete set, always fit the newer tyres to the rear wheels in order to reduce any loss of grip, which is more difficult to control at the rear.
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