July 20, 2017 at 8:13 PM
Everybody knows that modern cars are a world away from what we were driving around in 20 or 30 years ago in terms of reliability. While past generations carried a tool kit as a matter of course and accepted breakdowns as an inevitable part of motoring, today’s cars are extremely unlikely to let us down.
Except, that is, in one area. All that separates our car from the road outside is the set of tyres, and to all intents and purposes, these have changed very little over the years. Perhaps it is unsurprising, therefore, that defective tyres are the number one reason for MOT failures in the UK. In fact, more than one in ten cars that go for an MOT test fail for that very reason.
This is no laughing matter, as defective tyres affect handling and braking characteristics and can be the difference between life and death in the event of an emergency situation. Here, we offer some guidance on how to check whether yours are up to scratch.
We all understand that a tyre is a consumable with a finite lifespan, but just how long can you expect your tyres to last? This is like asking how long is a piece of string. It depends heavily on the vehicle, road conditions and driving style. Tyre manufacturer Michelin says the average tyre should last for about 25,000 miles.
Every mile you drive, your car leaves a tiny trace of its tyres behind, and over time, the tread gradually reduces. This effect is increased during cornering and braking, and is also affected by having the incorrect tyre pressures.
New tyres have a depth of around 7mm, and the legal limit is 1.6mm. However, it is best to replace your tyres if the tread gets down to 3mm, as when tyres are close to the legal limit, they are less able to disperse water effectively, so aquaplaning can be a bigger problem.
Most tyres have wear indicators incorporated into their construction. These are raised bars at the bottom of each tyre groove. When the tread is on a level with the bars, you know you are on the legal limit. While these provide a useful indicator, do not rely on them 100 per cent, as tyres wear unevenly.
Wear might be the most common concern, but it is not the only thing that can affect your tyres. Hitting a kerb, bumping over a pothole or driving over a sharp object can all cause damage, so check the sidewalls for blisters, splits or bulges. The tyre might remain inflated, but with damage like this, it can suddenly fail at speed or under emergency braking, with potentially lethal consequences.
If your tyres are over or under inflated, it will affect wear, as well as your steering and braking. Check your tyre pressures once a week, and if you have a conventional spare, don’t forget to check that too, as it can deflate over time, even when it is tucked away in the boot.