It’s easy to take your car tyres for granted, and an awful lot of people certainly do until they get a puncture, a blowout or an MOT failure as a result of them not being up to muster. When you stop and take a moment to think about your tyres though, they’re actually among the most important components of your entire vehicle. Tyres have a major say in how your car drives and handles, how well it stops and accelerates, how much fuel you use, how comfortable the ride is, and most important of all – how safe you and your passengers are during any journey.
Despite all that, you’d be amazed at just how reluctant some people are to spend any more money than they feel they absolutely have to on tyres. I once had the mechanics in my service department refuse to test drive a very expensive luxury 4×4 after a service because the tyres were so worn the small mettle wires were sticking out. The owner still refused to authorise them to supply and fit a new set, even though his tyres were completely illegal and ludicrously dangerous.
To help you become a little more aware of your tyres and their importance, here are some facts and statistics you might not know.
The business of tyres
An awful lot of car tyres are made, fitted, used and discarded every year in the UK alone. Just in terms of tyres being fitted to cars, some 40 million of them are fitted each year in the UK. Around 75 percent of them are replacement tyres and the other 25 percent are being fitted to brand new cars on production lines.
If we then consider every type of vehicle that needs tyres, a simply staggering 100,000 tyres are fitted to vehicles on average every single day in the UK. On top of this, a further 5 million part-worn tyres are fitted to UK vehicles every year, but more about that sort of thing later.
Tyres generally fall into three broad categories of premium, mid-range and value, and the breakdown of sales is actually a little surprising. Almost half of all tyres sold in the UK fall into the premium segment, 30 percent sold are mid-range, and the value category only accounts for the remaining 20 percent.
The legalities of tyres
Everyone knows that when tyres don’t have the legal minimum amount of tread on them you can get into trouble with the law, but are you sure you know what the rules actually are? Give yourself a small pat on the back if you know that the legal minimum tread depth here in the UK is 1.6mm, but do you know which parts of the tyre have to conform to that standard? In fact, the 1.6mm minimum standard applies to the central three-quarters of the tyre, so being below this right at the edges of the tyre isn’t going to get you into trouble with the law as long as the central section is okay.
Not all tyres are full of air
Although most tyres are filled with nothing more than compressed air, there are some tyres that are filled with nitrogen and some tyres have no air in them at all. In the old days tyres used to be made from solid rubber, but then someone discovered things would be much more comfortable if tyres were filled with air instead. Filling tyres with nitrogen keeps the pressure stable as nitrogen doesn’t expand when heated in the same way as compressed air does. Unless you drive something like a Bugatti Chiron or you are racing on a track competitively, filling your tyres with nitrogen is a bit of a waste of money for day to day road driving really.
Tyre markings and labels
You’ve probably noticed a bunch of numbers and letters written around the rim of every tyre, but do you know what all or any of these markings mean? Let’s use 195/55R/17/91H as an example of what you might see on a UK tyre.
The first three numbers are the width of the tyre in millimetres, so in this case, the tyre is 195mm wide.
Things then get a little more complicated as the next two numbers after the first slash are the aspect ratio. The aspect ratio is the height of the tire expressed as a percentage of the width. In our example the number is 55, so the aspect ratio is 55 percent of the 195mm width and that 55 percent, therefore, means 107.25mm.
The R after 55 in our example stands for Radial which is the construction type of the tyre, and most modern tyres are of this type so we won’t complicate things by going over rare exceptions.
Next, we have the number 17 between the second and third slashes, and this is simply the diameter of the wheel expressed in inches. In this case, the tyre is for 17-inch wheels, so it could be 15, 16, 18, 19, 20 or even higher, depending on the wheel.
The final two numbers (91 in this example) are the Load Index, and this is the maximum load the tyre is rated to carry when correctly inflated. These double-digit numbers refer to a specific weight, and 91 refers to a weight of 615kg. For what other numbers represent, you’ll have to refer to a tyre Load Index chart.
Different tyres are rated for different maximum speeds and the final letter in our tyre markings example here is H, which equates to 130mph. There are 15 different tyre speed ratings, with L being the lowest at 75mph and (Y) being the highest at 186mph+.
Unsafe tyres can be more expensive
Unsafe tyres can cost you a lot of money, and they can be even more costly in other ways. If you get a tug from the Old Bill for illegal tyres you can get 3 endorsement points on your licence for each illegal tyre, and the fines can be as much as £2,500 for each offending tyre.
Although cheap tyres can be an attractive proposition if you need to get a car through an MOT or just stay legal and you’re on a tight budget, how much do you consider your safety and that of any passengers to be worth? My service manager used call cheap tyres “Ditchfinders,” and you don’t need to be a professor of regional linguistics to work out what that means, do you? Quality tyres are not an expensive luxury; they’re really an investment in your safety and in helping to prevent avoidable accidents.
Expensive tyres can be three or four times as expensive as cheap ones, but you’re not just paying for a brand name; you’re paying for genuine quality.
The numbers add up
It’s impossible to say how many incidents are caused by defective tyres in the UK every year, or how many people are injured to varying degree as a result. What we do know though is how many deaths are caused by faulty tyres on average each year, and that number is a sobering 1,075. It’s not just a lack of tread that matters either. Accidents can because through damage to tyres, by fitting different types of tyre on the same vehicle, by having tyres under or over-inflated, or by having inappropriate tyres on for the conditions.
The MOT failure’s best friend
Your car failing its MOT isn’t necessarily a catastrophe, and it’s a long way from being the worst possible consequence of having poor tyres on your vehicle. However, it’s a prime indication of how many of us don’t pay enough attention to tyres when you learn that tyres are one of the most common reasons why vehicles fail MOT tests.
As many as 2.2million MOT failures each year can be attributed to tyres, but it still doesn’t mean you should consider your tyres to be fine just because they are at or just above the legal limit. Your tyre pressures being just 20 percent below the manufacturer’s recommended pressure is considered dangerous, regardless of the age or quality of the tyre.
Tyres are vitally important, and it’s vitally important that you don’t forget the fact. Your life, or the life of your passengers, could depend on it.