How to change a car tyre or use a repair kit

Thwump-thwump-thwump-thwump... if you've ever heard that noise from your wheels while driving, you know it normally means only one thing: you've got a flat tyre.

But there's no need to panic, and you may not need to call out a breakdown service either; changing or repairing a tyre is easier than you might think. Read on to learn how to change a car tyre safely by yourself, or fix a puncture with a tyre repair kit. 

We also give our top tips on keeping your tyres in good health, to help minimise the risk of problems in the first place.

Is a flat tyre the last straw for your current car? If you're considering replacing it, read our guide on where to buy a car.

What to do if you have a puncture

If you badly damage a tyre by striking an obstacle or particularly nasty pothole, it may deflate quickly. You’ll likely feel a tug on the steering wheel and will probably hear it as well – a bang or thud followed by a repeating ‘thwump-thwump’ sound.

If the tyre is deflating slowly, for instance after driving over a nail, the steering may just feel heavier than usual or drag to one side.

Either way, you’ll need to pull over and stop as soon as possible. Do so somewhere safe if you can, such as a lay-by or side street. Try to avoid stopping on a busy, fast or poorly sighted road.

If you’re on a motorway, pull as far over to the left of the hard shoulder as you can to maximise the distance between you and moving traffic, while still giving yourself room to access the flat tyre.

Turn your engine off, put your hazard lights on, engage the handbrake and put the car into neutral (or 'park' if you drive an automatic). Make sure everyone is out of the car and safely away from the road, and place a warning triangle on the road behind the car if you have one.

What you do next will depend on whether your car has a spare tyre or, as many modern cars do, a tyre repair kit. It will also depend how badly the tyre is damaged: repair kits only work with small holes, so if you can see a visible slash in the tyre and have no spare, you should call a breakdown service.

If this isn’t the first time you've been left stranded, you’ll appreciate the benefit of good breakdown cover. Discover which providers we recommend, in our guide to the best car breakdown providers.

How to change a car tyre safely

Our video guide takes you through how to change a car tyre, step by step. If you’re in an area with limited connection and can't see the video, our written step-by-step guide is below.

How to fit a spare tyre

Not all new cars come with a spare wheel. To save weight and cost, manufacturers now often supply a tyre sealant kit. If this applies to you, scroll down to read our step-by-step instructions to using a tyre repair kit.

1. Firstly, get out your spare wheel and tools, including the jack. They'll normally be found in the boot of the car, under the boot floor. Then grab your instruction manual, and thumb through it to locate the car's jacking point. The manual may also have instructions on how to change a tyre.
2. You’ll also need the adaptor for removing your car’s locking wheel nuts. This is normally located with the jack (unless you've moved it somewhere else for 'safe keeping'). Refer to the instruction manual if not.
3. Double check that your handbrake is fully engaged. Then, raise the car up by placing the jack under the jacking point closest to the wheel you're going to change. Rotate the jack's handle clockwise. Ensure the jack is resting properly on the ground as it takes the weight of the car.
4. Once the tyre you're changing has cleared the ground, remove any trim that covers the wheel nuts. Then use the wrench provided, and the locking wheel nut adapter, to remove them completely.
5. With the fixings removed, you should now be able to remove the wheel with the puncture and replace it with your spare. Be careful – a car wheel is normally quite heavy.
6. Reattach the wheel nuts and then lower the car to the ground. Once the car is lowered, tighten up the nuts, ideally working in a diagonal pattern. So, if your car has five nuts arranged in a star shape (which is quite common), tighten the first one, then move to the third, fifth, second and, finally, the fourth.

How long can I drive on a spare tyre?

Spare wheels supplied with cars are typically ‘space savers’ – narrower than normal and with a low speed rating, which will normally be marked on the wheel rim (typically 50mph). These tyres are only designed for emergency use, and won’t provide the braking or grip that a normal tyre will.

It's best to get the faulty tyre replaced and a full-size wheel put back on your car as soon as possible. Even if your car has a full-size spare wheel, we'd recommend visiting the garage anyway and getting the bolts re-tightened to the manufacturer’s recommended torque settings.

How to use a car tyre repair kit

Many cars are now sold without a spare wheel and are instead supplied with an emergency tyre repair kit. These typically consist of:

• Car tyre sealant – usually this is pressurised liquid latex, which may come with a connector to fit it to the tyre valve.
• Car tyre pump – a compressor powered by the car’s 12V socket, which will slowly reinflate the tyre once the hole has been sealed.

Using a repair kit is fairly fuss-free, but like a space-saver wheel, it's only a temporary measure. Go to a garage to get your tyre repaired or replaced as soon as possible.

If you don’t feel comfortable changing your spare wheel – particularly in a precarious situation like a motorway hard shoulder – tyre sealant kits and compressors are available cheaply at both online and at automotive retailers, and are a useful, less-labour intensive backup. We wouldn’t advice using tyre sealant on a punctured space saver, however.

Nor should you use a tyre repair kit if your car is fitted with ‘run flat’ tyres. These feature strengthened sidewalls and are designed to be driven for limited distances at low speed, even when deflated. These can be identified by markings on the sidewall, though these can vary between manufacturers.

Step-by-step: how to repair a car tyre puncture

1. Follow the same procedure for stopping safely as described above. Grab your repair kit – it's usually found under the boot floor.
2. Follow any provided instructions. In most cases, using it is simply a case of connecting the bottle of tyre sealant to the valve on the wheel rim. Most bottles are pressurised, so the latex will flow through the valve into the tyre.
3. Once inside the tyre, the sealant should find and seal the hole. Now, connect the compressor to the 12V socket. Start the engine, then the compressor, and pump up the tyre to the recommended pressure.
4. If the hole does not seal immediately, disconnect the compressor and try driving the car forwards or backwards a few metres to spread the sealant around the inside of the tyre. Then reattach the compressor and try again.

A tyre repair kit will often get you out of immediate trouble but is no good for holes larger than about 4mm. If you have a serious blowout or have damaged a tyre sidewall, you will have to call a breakdown service. Check out our guide on how to find good car breakdown cover.

How to check your car tyre pressure

Ensuring your tyres are at the recommended pressure is the easiest step you can take to maintain your tyres. It won’t prevent a puncture, but even if they’re only slightly underinflated, it can have a negative impact – not only on your fuel economy, but your car’s braking performance too.

Over-inflating tyres can mean they wear unevenly and may become more susceptible to damage from striking kerbs or sharp stones.

How do I know the tyre pressure for my car?

Your car's handbook will tell you the correct tyre pressures, or you may find it printed on a sticker inside the driver or passenger door. This will often include information on tyre pressures to use depending on the load you’re carrying and for different wheel sizes.

Some modern cars have built-in automatic tyre pressure monitors, but we recommend regular manual checks as well.

Ways to check your tyre pressure

A hand-held tyre pressure gauge is an easy way to determine whether your tyres need inflating – they're available from a range of online and physical retailers and typically cost less than £20. Simply attach the tyre pressure gauge to the valve on the wheel rim (after removing the dust cap), press down evenly to ensure a tight seal and read the measurement.

Alternatively, tyre pumps on petrol station forecourts will normally read the tyres starting pressure before you begin inflating.

How often should I check my tyre pressure?

Ideally, you should check your tyre pressure every couple of weeks, particularly if you drive your car regularly. It's also sensible to check before you embark on any long journeys. Check when the tyres are 'cold' (so they haven't been driven on for a couple of hours). If you need to drive to a petrol station to check the tyre pressure, choose one that's as close to your starting point as possible. 

How do I pump up my car tyres?

Automatic pumps at petrol stations and garages are normally the easiest and quickest way of inflating tyres. They’re normally coin-operated and allow the user to set the maximum pressure via a digital display. Pay attention as to whether the readings are in BAR or PSI – the two different measurements used.

Simply attach the hose to your wheel and the pump will do the rest. Most will even deflate a tyre if it detects it’s at a higher pressure than the user has set.

A foot pump is a low-tech (and very slow) alternative, but is a handy tool for inflating tyres at home.

Whichever method you use, it’s best to inflate a tyre when it’s cold. The pressure in tyres increases as they heat up, which could lead to false readings.

Car tyre maintenance and safety tips

Minimise tyre wear

To get the maximum mileage from your tyres, avoid harsh braking, rapid acceleration and fast cornering – all of these will increase wear.

Check your car tyres regularly for excessive or uneven wear. Remove any stones or debris wedged in the tread, and keep an eye out for any deep cuts or bulges. These can be signs of imminent tyre failure.

If you hit a kerb or bad pothole, you should make sure you haven't damaged a wheel. If the rim is scuffed, has it caused any sharp or rough edges? Any damage close to the tyre’s sidewall should be repaired quickly, and you should ask a garage to rebalance the wheel afterwards.

Monitor tyre tread depth

By law, your car tyres must have a minimum tread depth of 1.6mm in a continuous band across three quarters of the width of the tyre.

However, tyre performance deteriorates well before the legal minimum depth is reached, particularly in wet weather. This is because the volume of the tread grooves is reduced, so they are less effective at dispersing surface water from the road.

Don't wait for the MOT test to find out if your tyres are up to scratch. Check your tyres regularly and consider buying new ones before they reach the legal minimum.

Look after your spare tyre

The only thing worse than getting a puncture is when you go to fit the spare and discover that it has also gone flat. Check the spare regularly for pressure and condition, because if your spare is old, the rubber may begin to perish, resulting in potentially dangerous cracks in the tread or sidewalls. This is particularly relevant if your spare wheel is stored on the outside on your vehicle, as is the case with some large SUV models.

In need of a new set of wheels (literally rather than figuratively)? Check our car tyre buying guide for expert advice plus explanations of what car tyre markings mean.