a man checks his tyres are inflated and not deflated.

What are the risks of under-inflated tyres?

Driving with under-inflated tyres may seem harmless, but if you leave it for too long, you can have several problems on your hands before you know it!

Identifying under-inflated tyres early could help to improve safety as you get back on the road – read on to find out how under-inflated tyres affect your vehicle, and what you can do about it.

Uneven tyre wear

When you drive with under-inflated tyres, the sidewalls of the tyre can become misshapen and bulge out because there’s not enough internal air pressure to hold the correct tyre shape. As a result of the sidewalls bulging, the edges of the tyre tread get much more wear than usual because they’re in contact with the ground more often.

This can cause premature tyre wear in normal cars – but if left for too long, excessive wear can lead to tyre bursts in areas where the rubber is too thin to hold the pressure.
If you see any particularly bulging parts of your tyre, you should be very careful of them when driving and get them replaced immediately.

Poor fuel economy

This is another by-product of the tyres making more contact with the road. Because there’s additional surface contact with the road, there’s more friction, which means that there’s more force holding your car in place – or, rather, there’s more friction slowing your car down.

This, in turn, means that your engine must work harder to go at the same speed, so you end up using considerably more fuel than you should be.

Unresponsive steering

Because the tyre rubber has more slack in it when it’s in an unpressurised state (or at least a less-pressurised state), your steering will be more sluggish. That’s because it takes more of a side-to-side turn to actually turn the tyre itself.

Not using the correct pressure here means that it becomes harder to control your car at speed – it’ll seem like it’s bouncing around bends rather than holding its grip on the road.

What to do about under-inflated tyres?

There are a couple of options – you can either use a paid air compressor at a petrol station (they’re usually between 50p and £1 to use) or use a 12v compressor at home.

It’s a good idea to regularly check your tyre pressures. If you have a 12v compressor, it’ll usually be able to give you a current pressure reading just by putting it onto the valve stem of your tyre. It’s recommended to check your tyre pressures at least once a month.

Need to get your tyres checked?

If you need to get your tyres checked or replaced, get in touch with your local Kwik Fit centre. Tyre repair and replacement from Kwik Fit is included as part of your worry-free lease package.

Find out more about tyre repair and replacement included in your lease

Know your tyre size

Whether they’ve become worn with age or you’ve discovered a puncture, if you find you need a new tyre, the first thing you’ll need to know when replacing it is your tyre size. There are many different tyre sizes depending on the type of car you drive.

You won’t necessarily find the correct tyre size in the vehicle manual as there are usually several that can be fitted to each make and model of vehicle. The simplest and best way to tell what tyre size you need is to go and have a look at the sidewall of your existing tyre. The sidewall will include lots of letters, numbers and codes, but the one you are looking for is usually in large print and will look a little something like this:
Kwik Fit tyre image.jpg

In this instance the tyre size is 225/45R17 Y. While the numbers and letters may change, the format is always the same e.g. 195/70R14 T or 245/45R19 Y. The numbers and letters each represent a different aspect of the tyre’s size and properties including the tyre width, aspect ratio, rim size and speed rating.

When looking for the tyre size on the sidewall of your tyre, make sure you look at the markings on the tyre that needs replacing as they may not all be the same. On many makes and models of vehicle, the front and rear tyre size can actually be quite different in order to improve handling and stability. Tyres on the same axle should always be the same size however.  


About the Motability Scheme

The Motability Scheme supports families in staying mobile by offering a unique, all-inclusive leasing package for brand new cars from all the major manufacturers. If you care for a child or someone who doesn’t drive, you can be added as a named driver instead. And as well as cars from a range of manufacturers, cars with adaptationsWheelchair Accessible Vehiclesscooters and powered wheelchairs are available too.

If you’d like to find out more about the Scheme, request an information pack below and we’ll send you all the information that you need to make the right choice.

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