THE CAR DOCTOR
The Motorist's Best Friend

Google Ads

Tyres

Tyre Pressures

Most people know that it's important to regularly check their tyres for damage and punctures but how many know that they should be checking the tyre pressure too?

Why is Having the Correct Tyre Pressure Important?

Having the right tyre pressure can add ages onto the length of time that your tyres are operational for. Not only that, but it also improves the overall safety of your vehicle and helps you use less fuel, so is good for both the environment and your bank balance!

If you drive on tyres that are under inflated, they are prone to overheating. If they are over inflated they can cause you real problems steering and driving your car properly on the road, which could lead to an increased chance of a collision. It’s reported that around 6% of fatal accidents on the UKs roads are caused by under-inflated tyres suddenly failing, and it is such a problem that you could be fined £2,500 per tyre if they are over or under-inflated enough to be considered un-roadworthy.

So apart from the legal and safety aspects, there’s also a good financial case for checking your tyre pressure. Over and under inflated tyres are more likely to be damaged than those that are inflated to the correct pressure. Either extreme can also lead to excess tyre wear: under-inflated tyres will wear down quicker along the walls of the tyre, whereas over-inflated tyres will cause wear around the centre of the tyre. This is likely to lead to early replacements and cost you more money.

That’s not all though - driving with the wrong tyre pressure can also make your petrol bill higher! This is because under-inflated tyres increase rolling resistance and your car needs to use more fuel to maintain the same speed as when your tyres have the correct pressure. So to sum it all up, you can save money, stay on the right side of the law, remain safe, and even reduce your ‘carbon footprint’ just by making sure you have the correct tyre pressure. By having your tyres inflated properly you will, use less fuel and that means there's a good chance that your vehicle will produce less Co2 emissions!

The pressure of your tyres is measured by working out the amount of air that's been pumped into the inside lining of your tyres in BAR pressure or PSI (pounds force).

As with anything concerning the condition of the vehicle you are driving on the road, the onus is on you as the driver to make sure that the tyre pressure is correct, and is checked regularly - at least once a month, preferably once a week or whenever you think there might be a problem with your tyres.

During the summer, it's likely that your tyres will lose more pressure, so the hotter it is, the more often you need to check them. Usually air escapes at around 2lb of air per month, although because it happens so slowly you might not even be aware that it's happening.

Find the owner's manual and that should tell you everything you need to know. The information might also be marked on the inside of the car (check the pillar of the driver's door, the fuse box, or on the inside of the petrol flap). If not, you can always ask at a garage or do a search on the Internet, making sure that you are using a reputable site. In most cases, two different pressures are given - one is for driving with a laden vehicle (with several people or heavy items on board) and the other is for 'normal' driving conditions.

To check the current pressure, you will need a gauge. You can either buy one from a car accessory supplier (such as Halfords) or take the more convenient option - go and find a digital air dispenser - most supermarket garages and petrol stations will have one.

The law in Great Britain is very specific when it comes to tyres. It's such an important part of car maintenance to ensure that all tyres are in good condition that to drive with defective tyres carries a high penalty; currently a fine of £2,500 and a 3 penalty point endorsement per defective tyre (that's £5,000 and 6 points for 2 defective tyres, and so on).

Many people are caught out every year for simply not knowing that they are breaking the law in relation to the condition of their tyres - but ignorance is not an excuse. It won't stop you from being involved in an accident and it won't stop you from ending up with a hefty fine and penalty points on your licence. As set out in the Road Traffic Act 1988, as the driver of a vehicle it is your responsibility to make sure that it is roadworthy and you are liable to face legal action if you do not do so.

Worn or ‘bald’ tyres are called so because the tyre tread – which helps you to stop quickly in an emergency – has been worn down to an unacceptable level. Sometimes you can tell by looking that a vehicle has ‘bald’ tyres, but on the other hand, it can be really hard to tell just by sight alone – especially if it’s a close call. However if you are stopped by a police officer and your tyre tread is found to be below the legal limit, which for cars in Europe (including the UK) is 1.6mm, then you will face punishment as laid out in the first paragraph of this article – so it’s really worth your while to check your tyres regularly and make sure that they are road-worthy and safe.

All passenger tyres have little bars moulded into the tread called 'tread wear indicator bars'. They can be found in the tread grooves, near the bottom and in several locations on the tyre. If you look for these bars and find that the tyre is worn so that any of them are now lying flush with the tread ribs, then you need to replace your tyre as soon as you can. If you can’t tell, or want a professional opinion, just go to a repair garage, they’ll be happy to help you out and usually will do it for free.

If there is wear on both edges of the tyre, this means that it is likely that your tyre is under inflated. This reduces the life of the tyre because it wears away the outside edges of the tyre and plays havoc with the tyre durability because the edges get too hot. Having under-inflated tyres also makes your car work harder because it increases the rolling resistance and means you use more fuel than you should do. If you check your tyre pressure and all seems fine, then it might be that the vehicle is misaligned - you will need to take it to a garage to get checked out.

If there is excessive wear and tear in the centre of the tyre, this usually means that the tyre is over inflated as this makes the middle of the tyre load bearing and therefore runs it down faster than the rest of it. Again, this will reduce the life of your tyre and can lead to costly replacements, or worse, being involved in a tyre-related accident. Again, it could be a misalignment issue so if the tyre pressure is ok, get professional advice.

Sometimes known as scalloping, dipping or cupping, dips in the tread are usually found on the front tyres, and are a sign that the wheels may not be balanced correctly, or that the steering and suspension systems need to be checked out.

Unbalanced tyres can lead to problems with not only a vehicle's suspension system and tyres, but also to the driver as the constant vibration can lead to fatigue. If you feel any vibration while driving, have your tyre balance checked out as soon as you can.

If you do find a problem with your tyre - even a puncture, don't panic! It might be possible to save the tyre but you must go to a professional tyre fitter so that they can measure the damage and make sure that it is within the legal guidelines for repairing and replacing tyres.

Modern tyres are durable and quite reliable but there are still several things that can go wrong with them - blow outs and tread separating being the most common faults. Driving over a very bumpy or jagged road, or driving over a nail or some glass can give your tyre a puncture and in some cases cause it to burst or ‘blow out’.

If this happens you might be driving along quite happily when you suddenly start to realise that something is wrong with your car – maybe it starts to pull to the left or right, or you might just feel a significant change in the way it feels on the road surface. The first thing you need to do is check is that all your tyres are still in one piece.

The first thing you need to remember is to stay calm. Although it can be scary, dealing with a damaged tyre is easy if you know what to do and use your common sense. Bear in mind that if you find yourself getting a blow-out whilst driving along in the fast lane of the motorway, you not only have to get yourself to a position of safety, but you have to do so while making sure that you don't put any of your passengers or other road users in danger.

Below are some suggestions if you get a blow out or a tread separation while the vehicle is in motion.

First of all make sure it’s safe for you to change the tyre. If you’re on the motorway, call someone out. Hundreds of people are needlessly injured and killed by trying to carry out minor repairs on their cars while parked on the hard shoulder – it’s just not worth the risk. If you can’t get out of the road (maybe because there’s no hard shoulder or lay-by) then put your hazards on and move a safe distance away from the car while you wait for assistance.

The Car Doctor is operated by

The only homepage you'll ever need !

Have you been caught Speeding?

Free eBook

This eBook will tell you all you need to know to help you keep your driving licence!

Click Here