How to check your tyre pressure and tread depth

We’re all looking forward to getting away this summer. But before you go, have you checked your tyres?

Bridgestone tyre with a nail puncture

According to Highways England, only one in six drivers check their tyres before setting off on a long journey. A third confessed that they’re not confident checking their tyre pressure.

One in five breakdowns are caused by worn or incorrectly inflated tyres so for a smooth journey it's important to keep them in good nick.

This means carrying out regular checks on them and making sure they’re in good condition before a journey.

Regular maintenance on your tyres could save you trouble further down the line.

For example, driving on under or over-inflated tyres could lead to problems with your braking, tracking, fuel-efficiency and suspension.

Here’s how you check the condition, pressure and tread depth of your tyres.

 

What are the laws about tyres?

Because your tyres are pivotal to your car’s safety, the law is strict as to how they should be maintained:

  • Ensure that the tyres are the right type and size for your car

  • All tyres should have a minimum tread depth of 1.6mm, but try not to let them fall below about 3mm

  • All tyres should be inflated to their recommended tyre pressure.

If your tyres are found to be illegal, you could be hit with a fine of £2,500 per tyre and get three points on your licence.

So if you have four illegal tyres, you face being stung to the tune of £10,000 and being disqualified from driving. Even if you previously had no points on your licence, this could happen.

On top of all this, you risk your safety and the safety of others. And if that’s not enough, you might find any car insurance claim is invalidated if you have an accident with unroadworthy tyres.

Keeping your tyres in good nick should be part of your regular car maintenance routine. You should understand the various labels, markings and ratings on your tyres.

And, if any of your tyres isn't up to scratch, you might need to change it.

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How do I check the condition of my tyres?

This is easily done via a visual inspection.

Take a good look around each of the tyres and make sure that there aren’t any cuts, tears or bulges on any of them. Check for stones and nails in the tyres, as well as any damage to the side wall.

 

How do I check my tyre pressure?

It’s important to check your tyres when they’re cool, as that’s when you’ll get the most accurate measurement. Ideally, you should check them before you start your journey.

You’ll need to use a pressure gauge to get a measurement. You can buy one to use at home. Alternatively, petrol stations should have one that’s usually free to use.

The recommended tyre pressure is different for each car – there’s no one-size-fits-all figure.

You’ll likely find your recommended tyre pressures inside the driver’s door or inside the petrol cap. If not, check your owner’s manual or have a look online.

There might also be different recommended pressures depending on the season and the car’s load.

Unscrew the valve cap on the tyre and attach the gauge firmly to take a reading. 

If the reading is lower than the recommended pressure, inflate your tyres to match. If it’s higher, let some air out.

When you’ve finished, take off the gauge quickly so no air escapes, and replace the cap. Repeat on the other tyres, and then you’re good to go.

 

How often should I check my tyre pressure?

There’s no hard or fast rule about this, but it’s good practice to check them at least monthly. If you make it a regular habit, it’ll quickly become something you do automatically.

 

How do I check my tyre tread depth?

Your tyre tread is what helps keep you steady on wet roads. The tread channels water into the grooves of the tyre, giving you more control on the road.

If the tread wears down, this becomes less effective, increasing your braking distance and increasing the risk of skidding and aquaplaning.

The legal minimum tread depth for cars is 1.6mm across the central three-quarters of the width of the tyre, and across the entire circumference.

Once your tread gets as low as this, you need to replace the tyre.

Some manufacturers recommend that you swap your tyres after the tread goes down to about 3mm, as that’s when its performance starts to drop.

 

How do I measure my tyre tread depth?

The easiest way to measure tread depth is with the 20p test.

Place a 20p coin in the main grooves of the tyre. If the rim of the coin – the bit with ‘TWENTY PENCE’ written on it – disappears, your tyres should have enough tread depth.

Make sure that you check in at least three difference places along each tyre, as one part may be more worn than another.

 

How often should I check my tyre tread depth?

To be on the safe side, it’s worth checking your tyre tread at least every few weeks – and before each long journey you make.