Tyres are a source of great mystery for many of us. Tyre sizes, speed ratings, the huge choice of brands, tread patterns and the differences between each model of tyre can leave the average driver feeling completely baffled! Not to mention the dark art of checking tyre pressures or trying to work out the benefits of switching to winter tyres in colder weather. These are some of the reasons why drivers often neglect their tyres, but when you consider how critical tyres are to our safety out on the roads, it's clear that we should all be paying a bit more attention to those black rubber rings on each wheel. So, let's take some time to talk tyres and help demystify it all.
Your tyres should be set to a specific tyre pressure in order to perform safely on the road. If your tyre pressures are too high or too low, your fuel economy could suffer, your car could handle poorly, the tyres could wear unevenly or more quickly, or you could do damage that risks a puncture or blowout. You should check your tyre pressures regularly, at least once a fortnight but as often as possible. Let's look at it step by step.
1) Always check pressures before you start your journey while the tyres are cold. The recommended tyre pressure is most commonly listed on a sticker inside the driver’s door. Pressures increase when the tyres warm up, and you might get a false reading. You'll need a tyre pressure gauge and an air pump to hand - you'll often find them at petrol stations, or they're fairly cheap to buy from car accessory stores.
2) Remove the dust caps by unscrewing them from the valves. If you lose any dust caps, always make sure they're replaced, because they prevent damage to the valves.
3) Press the tyre gauge firmly on to the valve. You'll hear a brief hiss of air before you get your reading. Hold it on for a couple of seconds. Readings will either be in PSI (pounds of pressure per square inch) or in bar.
4) Use your pump to inflate your tyres to the correct tyre pressures. Check your owner's manual for the recommended readings for your car if you're not sure.
5) Put the dust caps back on, and don't forget to reset your tyre pressure monitor on the in-car computer if your car is fitted with one.
Tyre Tread Depth
When checking your tyre pressures, you should also check your tyre tread depth. By law your tyres need to have at least 1.6mm of tread across the centre 75% of the tyre surface, but it's recommended that you change your tyres once they get below 3mm, because tyre performance reduces substantially below 3mm. Illegal tyres will fail a MOT, or get you a fine and penalty points if they're spotted by the police. To check your tyre tread you need a tyre depth gauge, which is also available fairly cheaply at a car spares store. If you haven't got one to hand, then grab yourself a 20p coin.
1) Get yourself into a position where you can see the whole surface of the tyre. You can do this by turning the front wheels, but for the back ones you might need to get on the floor!
2) Press the gauge on to the tyre and take tyre depth readings at three points across the tyre surface, to make sure they are even. If they aren't the same across the tyre, the cause could be something as simple as the wrong tyre pressure, or it could be something like the tracking, wheel alignment or a suspension issue.
3) If you've only got a 20p, pop it on its edge on to the tyre. If you can't see the outer band of the coin, then your tyres are legal. If you can see it, then your tyres need changing urgently.
While you're checking tyre pressures and tread depth, take the time to check your tyres carefully for other signs of damage. Uneven wear can cause the inner cords of the tyre to become exposed, which often happens on the innermost part of the tyre and can be difficult to spot. Look for any cuts or slashes in the tread or sidewall, any screws or nails that might have punctured the tyre, and any weaknesses in the sidewall which will present as a bulge, or "egg" as some call it. If your tyres are old, they may show signs of cracking from sunlight and weather damage. If you see any of these issues, get your tyres checked immediately because they could be unsafe.
Hopefully this guide helps you make sense of how to check your tyres are safe. If you need a bit of help, feel free to get in touch with us here at Thame Cars. We've been fitting tyres for over 20 years, and we're happy to check the pressures, depths and condition of your tyres, and replace them if needed. We have a range of tyres in stock. Visit our website here for more information.