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How to check if your tyres are safe and legal

Uk motorists are pretty rubbish when it comes to doing their own simple checks to ensure their cars are in fine fettle. A few minutes spent each week can stave off big bills and potentially a big accident, but despite this we’re either too lazy or lacking in confidence to make the time.

Last summer we published a guide to those simple maintenance tasks that you can do yourself and no doubt you now avidly keep on top of your car’s fluid levels and lighting. You do, don’t you? Of course you do.
One thing that wasn’t covered in that blog was your car’s tyres, because they deserve an article all to themselves. Not only are poorly maintained tyres likely to cause a crash, but they’re also one of the most frequently overlooked safety-critical items on a car.
Despite this, according to Michelin, 36% of UK drivers have dangerously under-inflated tyres. During a single national roadshow put on by the tyre maker, over 4500 cars were checked, and just 34% had correctly inflated rubber – 6% had at least one puncture. Or to put it another way, two-thirds of the cars they checked were rolling on sub-standard tyres.
According to the Driver and Vehicle Standards Agency (DVSA), which administers the MoT test, more than a third of MoTs are failed and in half of cases it’s because of a minor issue that the owner could have sorted themselves. In 10 per cent of cases, a car fails its MoT because of a tyre issue such as a puncture or a lack of tread.
Keeping your tyres properly inflated can make a big difference to how much fuel your car burns. According to Michelin, UK drivers waste around 250 million litres of fuel each year – around £350m worth – by driving on under-inflated tyres. Fail to inflate your tyres properly and not only will they wear out faster, but the suspension, steering and brakes will also wear prematurely.
Tread carefully
Your tyre’s tread is there to give you grip in the wet. When the roads are streaming wet it’s the tread that channels this standing water out of the way to keep your car in contact with the road. The deeper the tread the more effective it is at preventing you from skidding or aquaplaning.
When you fit new tyres to your car they come with about 8mm of tread. By the time this has worn down to 1.6mm you have to replace your tyres although once the 3mm point is reached, wet-weather performance starts to deteriorate noticeably. So changing your tyres early is always a good idea, but not necessarily a practical one for financial reasons.
If you’re caught driving with illegal rubber you could be fined £2500 and get three points on your licence – and that’s for each defective tyre. So maybe spending five minutes checking your tyres every couple of weeks might not be such a bad idea. Here’s how to do it.

  • Make sure your tyres are cold by doing these checks before you drive it anywhere. Start by parking the car on level ground
  • Check all the way round each tyre for damage such as cuts, bulges and nails or screws. For this it might be easiest to have a friend drive the car slowly backwards and forwards
  • Look for uneven tyre wear, which could be a sign of a problem. You can always drop in and ask for help at a reputable tyre fitter, who will normally give advice for free
  • Next see how much tread is left; if the tyre has worn unevenly there’s a problem that needs expert attention. It might be that the tracking has been knocked out, which means the wheels aren’t running parallel with each other. If the wheel has been bashed against a kerb it can knock the tracking out. Or it could be that the rubber bushes in the suspension have worn, leading to the wheels running out of alignment.
  • Look for the small blocks set every so often within the tread; when these are flush the tyre needs replacing as it’s down to the 1.6mm legal limit. You should replace tyres in pairs ideally.
  • To quickly check a tyre’s tread depth, insert a 20p coin into the tread grooves. If the outer rim of the coin is covered by the tread your tyres are OK, but if the outer rim is visible you need fresh rubber
  • Finish by checking each tyre’s pressure when ‘cold’ – that is, when you’ve driven less than two miles. You’ll need a gauge for this; you can buy one for a tenner or the air machines at garages have one built in. The correct pressures will be in the car’s handbook, or may be on a sticker on one of the door jambs. Don’t forget to check the spare wheel, too.

Even if your tyres are in perfect condition at the start of a journey they could be damaged by the end of it. You could pick up a nail or if you hit a kerb the tyre can be damaged. As a result you could get a slow puncture or a damaged sidewall which could lead to carnage at high speed.
Even if you don’t drive lots of miles or your tyres appear to be in perfectly good condition, spend a few minutes every couple of weeks or so checking that they really are okay. Just a quick visual check of each tyre is better than nothing, to see if it’s running low on air. It could make the difference between completing your journey without problems, and things going very badly wrong.
Richard Dredge