Merityre Article Archive

Here’s a sobering thought. Summer or winter, rain or shine, all that lies between you and a short, damaging trip into the scenery is the equivalent of the area of four shoe soles. Yes, every car tyre has a ‘contact patch’ the amount of its treaded area that touches the road. This area is only the size of an adult’s footprint.

Let’s say your car weighs one tonne. Nobody weighs half a tonne and the soles of his or her shoes do a pretty good job, expect perhaps on ice or snow. Translated into car tyre terms, the four-sole area has to do much, much more. It’s unlikely, for example, that a road car could generate a cornering force of 1g. Under heavy braking, it’s quite possible for such a force to be generated. Moreover, the forces generated during acceleration and cornering can be very high. Your car tyres and their contact patches do more than a ‘pretty good job’. You don’t usually expect your shoes to keep you from slipping in adverse conditions, such as on gritty or diesel-soaked tarmac in extremes of temperature. Your car tyres do this on a regular basis.

Legally, each of your car tyres must have a minimum of 1.6 millimetres of tread across ¾ of the width of the tyre’s running surface. Not meeting this requirement can get you three penalty points on your licence, as well as a £2,500 fine…per tyre. So, four balding car tyres equals a lost licence and fines of up to £10,000.

In this context, the law could be called an ass. Why? Because just 1.6 millimetres of tread on a car tyre is cutting things fine when it comes to grip. The Royal Society for the Prevention of Accidents (RoSpa) put this to the test. They tried some emergency stops in a typical car on some typical surfaces. On smooth concrete, as some motorway stretches have, the car’s barely legal tyres took a distance of 46.6 percent more to stop than an equivalent car with good tyres. Similarly, on hot rolled asphalt, the worn tyres needed 36.8 percent more distance to bring the car to a halt. There’s no need to ask why RoSpa recommends a minimum tread depth of 3 millimetres.

This isn’t the only scenario where worn car tyres will struggle. Tyres are designed to act like water pumps in wet conditions, they can clear surface water from their contact patches. When this fails to happen properly, the tyre will ride on a thin film of water. If this happens, you’d feel the steering lighten, which is an indicator of what’s actually going on. When a car tyre is unable to cut through road water fast enough, it will aquaplane. Aquaplaning equals significantly reduced grip, as you might find out when you attempt to steer or brake.

Whilst it may seem to make sense to get the very most out of the treads on your car tyres, there is such a thing as false economy. Your car tyres have wear indicators, moulded into the treads. Take a look at them and, if the treads no longer stand proud of the tread wear indicators, it’s new tyre time. Running your tyres down to the legal minimum could cost you far more than you think.

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Merityre.co.uk are one of the  leading UK independent suppliers of car tyres. Why not visit their website for an online tyre quote or contact your nearest fitting centre.

Wheel alignment? Surely your car’s wheels are in line all the time? In fact, they aren’t necessarily. Speed bumps, kerbing, speed pads and general wear and tear on a car’s suspension and steering can put the wheels out of alignment. Misalignment may be felt as pulling to one side or another, and/or strange steering. In the longer term, your car tyres will suffer – bad wheel alignment can radically reduce tyre life.

So, how do you fix poor wheel alignment, thus making your car steer and brake better, as well as achieving maximum car tyre life? The good news is that car manufacturers provide a means of adjusting wheel alignment. The not so bad news is that you can’t correct poor alignment yourself.

Cue a visit to your local friendly tyre man. Good tyre bays (and garages) have the equipment to check and adjust wheel alignment. All you have to do is watch (or not, depending on your preference) and pay for the work. Then, drive away secure in the knowledge that your car is shipshape in the wheel alignment department.

What happens in a wheel alignment session? Generally, three things are checked, and adjusted as necessary. The first check establishes that the car tyres are vertical, as viewed from the front or rear. Sometimes, the tyres may not be truly vertical. Some cars’ tyres sit at a slight angle from the perpendicular. This is the camber angle, which can be adjusted to meet the car maker’s specification.

The second check involves another angle, the castor angle. Does your car run on castors? Technically, yes, the castor angle permits the wheels and tyres to return to straight ahead when the car is rolling with no steering input.  As you know, your front wheels turn from side to side in response to your turning the steering wheel. No matter how the wheels and tyres pivot, a line drawn through the centre of the axis on which they pivot won’t be vertical. The line has to lean backwards slightly and if it doesn’t, the steering will feel very odd. Again, this can be cured by adjustment.

The last check is on a figure called the ‘toe’. All car suspension has a small degree of flexibility built into it. So, if the car tyres are parallel at rest, the drag between them and the road as the car moves would cause this flexibility to allow the wheels to splay very slightly. You wouldn’t see this but your tyres would soon tell you all about it, by wearing out the inner edges of their treads. So, the wheels are usually set to ‘toe-in’, so they run parallel. If the tyres toe out, if the toe-in is too much or if the toe angle varies from side to side, the car tyres will wear out prematurely. Curing this is again a matter of adjustment.

Wheel alignment used to be checked with a special gauge that used a mirror and lens system. Nowadays, it’s common for car tyre bays and garages to measure the angles involved using laser equipment. Yes, accurate measurement is necessary. In some instances, worn suspension or steering components mean that a problem can’t be adjusted away. Then, the tyre man in question will tell you what needs repairing or replacing for accurate alignment to be achieved.  It’s also the case, especially on a car with independent rear suspension, for the rear wheels and tyres to be misaligned. Once again, adjustment is usually possible.

Is it possible to stop your car’s wheels becoming misaligned and making the tyres suffer? In a word, yes. Don’t kerb your car tyres. Avoid potholes and traverse speed pads carefully. Above all, always negotiate speed bumps with the tyres on one side of your car. Straddling speed bumps is a major cause of both wheel misalignment and tyre carcass damage. You have been warned!

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Merityre.co.uk are one of the leading UK independent suppliers of car tyres. Why not visit their website for an online tyre quote or contact your nearest fitting centre.

Last night’s frost warning was a harbinger of the approach of winter. Here in the UK, we should be used to harsh conditions. However, give us an inch (of snow) and the miles aren’t covered…the country tends to come to a grinding halt. Is there a solution? Well, the increasingly popular winter car tyres may help.

This begs a question: are winter tyres genuinely useful or are they just a way of extracting more money from we motorists? Let’s see.

Recommended in Andorra, Italy, Norway and Switzerland, winter tyres are compulsory in Austria, Germany and Sweden and mandatory in Finland. These rules naturally apply on snow-covered roads and/or during the snow season. Often, there is the distinction that the tyres must be marked ‘M&S’ (no, not Marks and Spencer, the marking stands for ‘Mud and Snow’.) Newer snow tyres may have a symbol of a snowflake in front of a mountain. Currently, the distinction between winter and snow tyres is a touch unclear. A good tyre bay will advise you of the exact designation and specification.

In fact, specification is what winter tyres are all about. Car tyres in general are made in much the same way but the rubber compounds used and the tread patterns vary. Winter tyres are made with a high silica content. The probable tread pattern has two tricks up its sleeve. One is a more aggressive tread pattern than ‘summer’ car tyres. This is present to enhance grip.

The winter car tyre tread’s second line of defence involves a winter tyre key word, flexibility. When ordinary tyres have to work in temperatures below 7 degrees centigrade, they stiffen up in the cold conditions. In winter tyres, the compound and tread pattern both improve flexibility.

The benefit of winter tyres is that they give better grip in cold conditions, in rain as well as when snow and ice are about. There are plenty of subjective reports concerning car tyres and most of those concerning winter tyres are favourable. In some cases, cars found to be pretty hopeless in snow are transformed!

Are winter tyres the car tyres for all seasons? Their name offers a huge clue here. Summer tyres will outperform winter ones on dry roads and in reasonable temperatures, and winter tyres, having a softer compound, will naturally wear faster. This suggests following the lead of many continental drivers. They have two sets of tyres, one for winter, one for summer.

This brings us, in turn, to a potentially superior arrangement, which is also popular on the continent and in some cases is a legal requirement. Generally speaking, car tyres can handle most road conditions. However, in the depths of winter, the environment down at road level can be especially harsh. Car tyres may be able to cope with the salt and grit that gives some winter grip but our alloy wheels can suffer. Many popular cars have base models that wear steel wheels. One solution is to have a set of winter tyres on these. A set of steel wheels, with winter tyres, balanced and ready to roll can be fitted when the thermometer starts to plummet. With these ‘winter wheels’ fitted, your car can take on whatever the season has to throw at it, while your pristine summer wheels can live in cool, dark storage, ready for Spring. Bear in mind that suitable wheel nuts/bolts will have to be factored into the equation.

What’s the bottom line? Assuming you need to use your car in the off season, winter car tyres are worth the investment.

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Merityre.co.uk are one of the leading UK independent suppliers of car tyres. Why not visit their website for an online tyre quote or contact your nearest fitting centre.

All car tyres have them but not everyone knows what the markings moulded in a tyre’s sidewall means. At the very least, it is necessary on many cars to check the sidewall as the tyre pressure to be used can relate to the tyre size. However, this little trip through the meaning of the markings will inform, especially when the time to buy new tyres arrives.

Here, we can use a theoretical, typical car tyre. Let’s say it’s marked 185/55R13 91 H. Confused already? Don’t be, things will become perfectly clear! Take the tyre markings one by one….

185 – This is the width of the tyre’s section in millimetres, i.e. the width of the carcass of the tyre, not its tread’s width. 185 millimetres is a little over seven and a quarter inches.

55 – This figure refers to the tyre’s aspect ratio, which is the height of the tyre height expressed as a percentage of its width. 55 is a low-ish profile but aspect ratios can go as low as 30%. Low profile car tyres grip well and deform little but the cost is reduced ride comfort and poor protection against potholes, kerbs and road debris.

R – This couldn’t be simpler. Here, R means radial.

13 – This number refers to the diameter of wheel the tyre will fit. Why this is expressed in inches rather than millimetres isn’t clear but it is standard practice.

91 – This is the tyre load index, a code for the maximum load capacity of the tyre when driven at its maximum rated speed. The figure 91 means a rating of 615 kilograms.

H – This final marking shows the tyre’s speed rating. This H rating means the tyre can cope with extended use at a maximum speed of 130 miles per hour (210 kilometres per hour). The highest possible speed rating is Z. Car tyres thus marked are capable of maintaining 150 mph (240 kph).

There are numerous other markings on a car tyre’s sidewall, some of which are for the tyre fitter’s information. For example, if the tyre has a specific direction of rotation, there will be an arrow. A ‘TWI’ marking denotes where the tread wear indicator(s) are moulded into the tyre’s tread. A coloured dot will show the tyre fitter where the tyre casing should sit on the wheel in relation to the valve. There will also be ECE (not EEC) type approval markings, possibly special construction markings, such as M&S (Mud and Snow), and a maximum pressure marking.

One marking that could be of interest to you is the DOT code. The last four numbers in this show the tyre’s date of manufacture. Four-digit codes began after 2003 so if your new car tyre has the code 2 5 0 9, it was made in the 30^th week of 2009. Tyres over 6 years old must never be used.

All very interesting but do these markings matter to you? Apart from the aforementioned tyre size vs. tyre pressure element, the speed and load ratings are extremely important. Why? Because at best, using under-specified tyres is illegal and can invalidate your car insurance. At worst, the wrong kind of tyre can fail and cause a potentially lethal accident at high speed.

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Merityre.co.uk are one of the leading UK independent suppliers of car tyres. Why not visit their website for an online tyre quote or contact your nearest fitting centre.

‘There are lies, damned lies and statistics.’ Mark Twain claimed Benjamin Disraeli said this in the 19^th Century. True, some say that statistics can be misleading but they can also be sobering, to say the least.  Take, for example, this figure, released in September by the Department for Transport. Apparently, illegal, defective and underinflated car tyres caused over 1,210 road casualties in Great Britain during 2010. Over the last five years, 164 motorists have died as a result of having defective car tyres, 18 of those deaths occurring in 2010, according to the Road Casualties in Great Britain report.

What can be done about this? Well, October is Tyre Safety Month. Not for profit organisation TyreSafe was established in 2006 and is now one of the UK’s leading tyre safety organisations. As its chairman Stuart Jackson says, “The latest figures are truly shocking and emphasise why we need ongoing action, education and awareness about tyre safety issues.”

TyreSafe is working hard to ensure that we are informed about the importance of looking after ourselves and the safety of others by looking after our car tyres. As part of Tyre Safety Month, drivers will be given a free tyre safety check. Where? Hundreds of tyre dealers and garages are taking part, so try your local ones.

There are also a number of online resources, to show you how to carry out critical car tyre safety checks quickly and easily. An enlightening online video, of a car being driven on ice, demonstrates the benefits of winter tyres.

Stuart Jackson continues, “If all drivers took just a few minutes every month to check their tyre pressures, condition and tread depth, we could help prevent this needless injury and loss of life. Our website contains some really simple guides to help drivers understand what to look for.”

Tyre Safety Month is as much about education as awareness. The abovementioned website has material that will leave you fully informed about your car tyres and safety. You can learn about checking your tyres’ tread depth and ensuring they contain the correct tyre pressure. There are also TyreSafe’s ‘Magnificent 7 Car Tyre Safety Tips’.

As we all know, the tail end of the summer season heralds the onset of poorer weather. We should also bear in mind that the need for car tyre safety monitoring will continue ad infinitum…it won’t go away when November blusters its way in. In the short term, you can take a look at the TyreSafe web site. In the longer term, you may want to consider investing in a set of winter tyres. Or you could reflect on the wisdom of looking after the tyres you already have, keeping them in prime condition and being aware of the need to replace then as and when necessary.

The bottom line is this. As has been said time and time again, your car tyres are all that are ultimately keeping you on the road. Assuming you have no desire to become a statistic, neglect them at your peril.  Why not take a look at keeping your tyres safe– it might just be a life-saving bit of browsing.

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Merityre.co.uk are one of the leading UK independent suppliers of car tyres. Why not visit their website for an online tyre quote or contact your nearest fitting centre.

In these grim financial times, making a good deal is practically compulsory. Here is news of a deal which can save your car tyres, save you money and perhaps even save your life. That this can be done with the aid of just twenty pence may seem too good to be true. That you needn’t actually spend the twenty pence is downright unbelievable. Or is it…?

The law relating to car tyres in the UK couldn’t be clearer. Your tyres must have a minimum of 1.6 millimetres of tread all round the central three quarters of their circumference. If they have less than this, you are breaking the law. That you are also in greater danger of being involved in an accident should be taken as red. Perhaps it isn’t but, as money talks, let’s look at what else breaking the law can cost you.

If you have less than the abovementioned amount of tread on your car tyres, you are risking a fine of up to £2,500, and three penalty points on your driving licence. This applies not to all of your tyres but to each individual illegal tyre. Apart from the obvious cost, there would be a less evident one. Insurance companies don’t like lawbreakers. There are no prizes for guessing where your insurance company will hit you when you tell them about your brush with the authorities.

How can you avoid such unfortunate outcomes for twenty pence? It just so happens that TyreSafe, the organisation running Tyre Safety Month, has come up with a neat and simple test. Have you got a twenty pence piece? Take a look at it. You’ll see that there is a broad rim around the edge on each side of the coin. If you were to put the edge of the coin into one of your car tyre’s treads, you shouldn’t be able to see the coin’s outer rim. If you can’t see it, your tread depth is fine. If, on the other hand, if you can see the outer rim, the tread depth is questionable; you need your car tyres looked at by a pro.

In this instance, you probably have a readily available, simple tyre tread depth gauge in your pocket. Though it’s a coin of the realm, there is no need to spend it…and your car tyres’ fitness for their purpose will have been verified.

There is a further use for twenty pence, though you have to spend it this time. Getting up close and personal with your tyres may not be the most alluring task but neglecting it can have dire consequences. Most garage tyre pressure machines will give time enough to check all four tyres – and probably the spare – for a mere twenty pence. Get into the habit of checking your car’s tyre pressures once a month, and before each long journey. You never know, you might be lucky enough to come across a free air supply.

So, thanks to TyreSafe for reminding us that our tyres need nurturing. Remember that although October is Tyre Safety Month, the need to look after your car tyres is ongoing.

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Merityre.co.uk are one of the leading UK independent suppliers of car tyres. Why not visit their website for an online tyre quote or contact your nearest fitting centre.

Formula One teams spend vast amounts on research and development. They spend on aerodynamics, on construction with composite materials, and on wringing the maximum amount of power from their engines. We must, however, remember that in Formula One, tyres remain the largest single performance variable.

So, car tyres are car tyres, right? Not quite; road car and racing car tyres are distant relatives at best. Road car tyres are made to last, typically for a life of 16,000 kilometres or more. Formula One car tyres are made to last 200 kilometres at most, but they are made to be both light and strong. Their internal nylon and polyester structure, with its complicated weave pattern, is designed to handle much greater forces than a road car tyre faces. Let’s put it this way, no road car is likely to generate a tonne of downforce, or 5g of longitudinal load…or 4g lateral loadings.

F1 car tyres’ soft rubber mix is there to offer maximum grip, at the cost of a limited life. The tyres wear very quickly. They also become very hot but this is meant to happen – cold race tyres offer little grip. By way of example, the dry grooved tyres used until recently were designed to run at between 90 and 100 degrees Centigrade. Look carefully at the TV footage and you’ll see the cars’ tyres, pre-race, clad in special coverings, which are electrically heated. The need for heat explains why Formula One cars can be seen weaving from side to side on the way to the starting grid. The drivers are perfectly sober and they aren’t playing – they’re just warming their tyres.

Slick tyres, those with no tread at all, offer maximum grip. However, it was decided in 1998 that slicks be outlawed. Grooved tyres were made de rigeur, to help improve F1 racing as a spectator sport by reducing cornering speeds. This made life difficult for the tyre makers. The rules specified that all tyres had to have four continuous grooves at least 2.5 millimetres deep, spaced 50 millimetres apart. So, tyre manufacturers had to adopt harder rubber compounds, to maintain tyre integrity. By the 2009 season, slick tyres came back. The FIA, Formula One’s governing body, decided to use limits on F1 car aerodynamics as a means of keeping cornering speeds down.

How ‘soft’ or ‘hard’ the rubber compounds in F1 car tyres are, is varied by race, according to each track’s characteristics. For each Grand Prix race weekend, teams choose from two different compounds, and every driver must use both during the race. What makes the difference in the hardness of the different specifications? A change in the proportions of ingredients added to the rubber mix. Of these ingredients, the three main ones are sulphur, carbon and oil. In general, more oil equals a softer tyre compound.

Formula One car tyres are obviously run at the appropriate pressures. However, air pressure isn’t quite the right term. F1 car tyres are inflated with more nitrogen gas than air. This gas and air mixture is less susceptible to pressure loss and minimises the pressure differences that come about through temperature changes.

As will have become clear by now, there are huge differences between road car tyres and Formula One car tyres. They may share basic characteristics but the common denominators between them are certainly low on the scale.

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Merityre.co.uk are one of the leading UK independent suppliers of car tyres. Why not visit their website for an online tyre quote or contact your nearest fitting centre.

Many people take their car tyres for granted, but there’s far more to them than meets the eye. Knowing how they are made will illustrate this point.

How is a car tyre made? Production starts with a halobutyl rubber sheet that has special air-retaining additives. This sheet forms the tyre’s inner liner. A three-layer body ply comes next, in which a central layer of reinforcing fabric is sandwiched between two layers of rubber. Cotton used to be the material of choice for the reinforcing fabric but this has been replaced with Nylon, Rayon, polyester or even Kevlar. The body ply’s role is to give the tyre strength and flexibility; two such plies may be used in a tyre.

The acceptable faces of the tyre, the sidewalls, include antiozonants and antioxidants to enhance their life. The sidewalls can resist chemical attack and abrasion, and the tyre’s ratings and size codes are moulded into them.

Of course, the tyre’s sidewalls need to form a seal on the wheel rim. Bands of high tensile steel wire, copper or brass coated for corrosion resistance, form the beads on the inner diameter of the sidewalls. The triangular rubber section that joins the beads to the sidewalls is called the apex. The bead structure is what forms an airtight seal with the wheel rim.

Now for the tread and its underlying structure. The belt package is the part of the tyre that sits inside the tread. It’s made up of two layers of rubber that enclose a layer of steel cords. These cords run radially in the belt package, hence the term ‘radial tyres’.  The belt package is a major player in the tyre’s strength. The tread pattern is visible but the rubber compound used to make it is just as important. The choice of compound is a matter of a selecting a balance, between hardness (wear) and (grip). Think ‘compromise’.

These are the parts of a tyre and they must obviously be assembled and made into a tough, resilient structure. This procedure begins with wrapping the inner liner, body ply(s), sidewalls and beads around a special drum. Then, the belt package and tread are added, and the various elements are spliced together. At this stage the tyre is yet to be cured, and is known as a ‘green’ tyre. In this state, it is inflated and shaped.

Curing comes next, to bond the various parts of the tyre into a coherent whole. A rubber bladder is inflated inside the tyre, forcing it into a mould. Hot water, steam or an inert gas is used to inflate this bladder, and the curing process involves a great deal of heat and pressure…350 degrees Fahrenheit and 350 pounds per square inch to be precise. The curing process takes about 15 minutes.

The final stage is to test the cured tyre on a mock road surface, to seek out localized inflexibility and significant imbalances. Every tyre is given a visual inspection and sometimes, an X-ray inspection too.

So, car tyres are built tough to be tough, which they must be to take on the tough job they do. As they are all that keep your car on the road, it’s reassuring to know how much effort and care go into making them.

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Merityre.co.uk are one of the leading UK independent suppliers of car tyres. Why not visit their website for an online tyre quote or contact your nearest fitting centre.

‘Blowout’. It’s a funny word. Unarguably a noun, it means…

1a.  A sudden rupture or bursting, as of car tyre.

1b.  The hole made by such a rupture.

2.  A sudden escape of a confined gas or liquid, as from a well.

3. Slang A large party or other social affair.

4. Informal A lopsided victory or thorough defeat.

Here, we are concerned with part 1a of the definition. Blowouts are less common than they used to be but the usual suspects cause them. These are under inflation, overloading, impact damage, structural damage or a big puncture.

You’ll notice that these factors have one thing in common. All cause or lead to a sudden loss of air pressure in the car tyre. The common denominator in any blowout is that it happens suddenly. The cause matters in that by taking care of your tyres means you can often avoid the risk of a blowout. Here, ‘taking care’ means keeping your tyres correctly inflated, and inspecting them frequently to look for cuts, bulges and other significant damage. Remember that a careful inspection should follow any known or suspected impact, such as with a kerb, road debris or a pothole.

Should the worst happen and one of your car tyres deflates quickly, your response can make the difference between a safe, controlled stop and a one-way trip into a ditch or worse.

Picture the scene. You’re driving along, minding your own business. Suddenly, you hear a tyre letting go. BANG…hiss…flap…flap…flap! Your natural reaction will probably be to hit the brakes and try to wrestle with the steering wheel, which will be suddenly pulling to one side. WRONG!…and it makes no difference whether your driving a sports coupe or a big luxury car. Your natural reaction is…well, natural but it can be very dangerous.

The trick is to first of all follow the well-known advice of Corporal Jones in ‘Dad’s Army’. Instead of panicking, briefly dab the accelerator, or at least don’t lift off it. Maintaining the car’s momentum will let you keep in the lane in which you were travelling when the blowout happened. You’ll have to apply counter steering to fight the car’s natural tendency to veer off line but you’ll find that you can still follow a reasonably straight track and keep the car stable. Then, gently ease off the accelerator and let the car slow down gently.

At this point, it’s a great idea to activate your car’s hazard lights. Your car should still be under control but you’ll have to stop pretty soon and the hazards will tell other drivers that not all is well. Ignore the noise and debris emanating from your wrecked car tyre. You can then pull over to the side of the road as soon as you find a safe place to stop. Under the circumstances, it’s OK to drive on for a short distance; the failed car tyre will be history anyway.

Finally, it’s no good heaving a sigh of relief at having survived a blowout, only to be killed by a passing truck while trying to replace the wrecked car tyre. Never attempt to change a tyre on a busy road. Call out your breakdown provider if you can’t reach a safe, quiet place to fit the spare wheel.

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Merityre.co.uk are one of the leading UK independent suppliers of car tyres. Why not visit their website for an online tyre quote or contact your nearest fitting centre.

According to research carried out in May 2011 it’s official. What’s official? That we don’t all maintain our car tyres properly and this is proving costly in more ways than one. For their study, statisticians checked out 2,700 car tyres across the UK and uncovered some disturbing statistics.

The study showed that more than two thirds of cars in the UK are being driven with tyre pressures at least 3 psi below the manufacturer’s recommendation. According the study, the average amount of under inflation is 5.75psi, a staggering 18 per cent below the recommended figure. It is estimated that UK motorists are wasting £993 million on additional fuel to compensate for the drag caused by under inflated car tyres. Under inflation can also cause poor braking and handling, and can lead to tread damage and even blowouts. The study also found that nearly ten per cent of cars had a difference of  10 psi or more between tyres on the the same axle. If you’ve ever driven a car with such a prssure mismatch, you’ll know how unstable it felt.

Over inflation of car tyres also reared its ugly head. The study revealed that one in seven cars are tottering around with at least one tyre that has 3 psi or more pressure in it than the manufacturer recommends. This can quickly cause irregular tread wear and may lead to bulging of the tyre’s sidewalls.

The car tyre that’s usually out of sight and therefore out of mind was also found to be lacking, specifically in terms of air pressure. On average, the spare tyre was under inflated by a whopping 18 psi, 44 per cent lower than the recommended average pressure of 44 psi. So, many a driver needing to use the spare tyre could be in for a nasty shock. Fitting the spare wheel and carrying on regardless on a soft tyre may not be grounds for an immediate accident but it remains potentially disastrous.  It’s worth noting that space saver spare tyres generally have to be inflated to a much higher pressure. This, probably up to 60 psi, is almost twice the pressure used in a conventional car tyre.

Should a car tyre prove incapable of holding its pressure, this could be down to a puncture or slow leak at the valve. Such problems are usually cheaply and easily fixed at a good tyre bay. For those concerned about the pressure in their spare tyre, there’s the option of having it inflated with nitrogen. The molecules in nitrogen are both bigger and drier than those in normal compressed air, so the tyre will maintain its correct pressure for longer.

So, in among these sobering statistics, is there an encouraging figure? In short, is anybody getting it right? There is but it hardly makes for any degree of self-congratulation. According to the study, there are motorists driving around with all four car tyres inflated to the recommended pressure. However, haloes are thin on the ground…only four per cent of the motorists surveyed could boast that they were travelling on correctly inflated tyres.

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Merityre.co.uk are one of the leading UK independent suppliers of car tyres. Why not visit their website for an online tyre quote or contact your nearest fitting centre.