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.
Article Resource
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.
Wednesday, 14 September 2011
Top Tyre Tech: Facts About Formula One Car Tyres
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.
Article Resource
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.
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.
Article Resource
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.
Thursday, 11 August 2011
Worst Case Scenario – How To Cope With a Blowout
'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.
Article Resource
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.
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.
Article Resource
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.
Under Pressure: UK Motorists' Shortcomings Revealed
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.
Article Resource
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.
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.
Article Resource
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.
Friday, 15 July 2011
High Flyers on Car Tyres: More Star Cars
There are a great many movie star cars but some are rather less well known than others. All have put tyres to tarmac on screen and many still do off screen. Here are three star cars that perhaps aren't quite as familiar as some of their competitors.
Our first contender is the car that never was, in production terms at least. The Toyota 2000GT attracted a lot of attention when it first appeared in 1967. At the time, Japanese motor manufacturers were known for producing practical (i.e. boring) and derivative models. When 'Road and Track' magazine tested the 2000GT, it was described as, "One of the most exciting and enjoyable cars we've driven." It was also favourably compared with Porsche's 911. So, where have you seen a Toyota 2000GT on screen, spinning its tyres as competently as all the rest? You saw one in 'You Only Live Twice'. This white convertible was driven by James Bond's girlfriend Aki (Akiko Wakabayashi), with Sean Connery in the passenger seat. Why was it the car that never was? The Toyota 2000GT was a coupe that was too low for the 6ft 2 in tall Connery to fit into comfortably. Yamaha – who built the car – tried making a targa-top version but Bond's head still protruded far above the windscreen, giving a rather ridiculous look. So, just two 'convertibles' were built especially for the film. Look very closely and you'll see that the car's folded 'hood' is nothing more than an upholstered hump.
Sticking with Bond film trickery, can a car really become a submarine? In 1977, 'The Spy Who Loved Me' would have had us believe one could. The Lotus Esprit S1 concerned tucked its tyres into its wheel arches (which magically filled themselves in), sprouted hydroplanes and apparently went diving. In reality, there was a real roadgoing Lotus Esprit S1, and a heavily modified body shell for underwater use. This shell was fired off a jetty using a compressed air cannon. The underwater mock-up was able to drop 'depth charges' but it had no real submarine abilities and no engine. Perhaps appropriate in a movie in which the villain was named 'Stromberg' – also the name of a kind of carburettor!
In the same year, 'The Car' was burning tyres and rendering audiences awestruck. The possessed star car in this average schlock-horror shocker (also known as DeathMobile) was based on a 1970-ish Lincoln Continental Mk III. In fact, four cars were built, two being destroyed during filming. The main stunt car featured a 460 cubic inch V8 engine, a roll over bar, heavy-duty suspension and amber-tinted glass. A locked 4.11 to 1 differential allowed for easier tyre spinning. The fourth and last car was based on a late 1970s Ford Thunderbird. It was loosely assembled, to be shot over a cliff for the final scene. The shop behind all this heavy metal was Barris Kustoms in North Hollywood. Barris was also responsible for building the original Batmobile, The Munster's Koach and the Green Hornet car, 'Black Beauty'. The 1977 invoice for 'The Car' shows it cost '$84,000.'
Article Resource
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.
Our first contender is the car that never was, in production terms at least. The Toyota 2000GT attracted a lot of attention when it first appeared in 1967. At the time, Japanese motor manufacturers were known for producing practical (i.e. boring) and derivative models. When 'Road and Track' magazine tested the 2000GT, it was described as, "One of the most exciting and enjoyable cars we've driven." It was also favourably compared with Porsche's 911. So, where have you seen a Toyota 2000GT on screen, spinning its tyres as competently as all the rest? You saw one in 'You Only Live Twice'. This white convertible was driven by James Bond's girlfriend Aki (Akiko Wakabayashi), with Sean Connery in the passenger seat. Why was it the car that never was? The Toyota 2000GT was a coupe that was too low for the 6ft 2 in tall Connery to fit into comfortably. Yamaha – who built the car – tried making a targa-top version but Bond's head still protruded far above the windscreen, giving a rather ridiculous look. So, just two 'convertibles' were built especially for the film. Look very closely and you'll see that the car's folded 'hood' is nothing more than an upholstered hump.
Sticking with Bond film trickery, can a car really become a submarine? In 1977, 'The Spy Who Loved Me' would have had us believe one could. The Lotus Esprit S1 concerned tucked its tyres into its wheel arches (which magically filled themselves in), sprouted hydroplanes and apparently went diving. In reality, there was a real roadgoing Lotus Esprit S1, and a heavily modified body shell for underwater use. This shell was fired off a jetty using a compressed air cannon. The underwater mock-up was able to drop 'depth charges' but it had no real submarine abilities and no engine. Perhaps appropriate in a movie in which the villain was named 'Stromberg' – also the name of a kind of carburettor!
In the same year, 'The Car' was burning tyres and rendering audiences awestruck. The possessed star car in this average schlock-horror shocker (also known as DeathMobile) was based on a 1970-ish Lincoln Continental Mk III. In fact, four cars were built, two being destroyed during filming. The main stunt car featured a 460 cubic inch V8 engine, a roll over bar, heavy-duty suspension and amber-tinted glass. A locked 4.11 to 1 differential allowed for easier tyre spinning. The fourth and last car was based on a late 1970s Ford Thunderbird. It was loosely assembled, to be shot over a cliff for the final scene. The shop behind all this heavy metal was Barris Kustoms in North Hollywood. Barris was also responsible for building the original Batmobile, The Munster's Koach and the Green Hornet car, 'Black Beauty'. The 1977 invoice for 'The Car' shows it cost '$84,000.'
Article Resource
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.
Car Tyres In Law: Your Legal Obligations
What hurts more, being fined for using illegal car tyres or paying out so your car tyres are legal and safe? In practice, the latter cancels out the former. However, it pays to know what the law requires of you in relation to your car's tyres. Here is a breakdown of the legal necessities as regards car tyres.
Driving on worn or damaged tyres can attract a fine (or an MOT failure) and it can also place you firmly in breach of your car insurance policy's conditions. Both these events matter but something else you may be doing is of far greater importance. Never forget that using tyres that are of the wrong type, are damaged or are worn endangers lives.
Important Points
What makes a car tyre poor? Several aspects can put a tyre in this category but there are important factors you need to consider…
Car tyres must not have any lumps, bumps or tears caused by separation or partial structural failure.
They must not have a cut or tear longer than 25 millimetres, or longer than 10 per cent of the width of the tyre's section (whichever is the greater). No such damage may be sufficiently deep as to reach the tyre's internal cords.
No part of the tyre's internal plies or cords may be exposed.
Any tyre must be compatible with the type of tyres fitted to the other wheels
Any tyre, on a car or trailer, must be fit for purpose and free from any defect that might endanger any person or damage the road.
Legal Tyre Maintenance
All car tyres have to be correctly inflated, to the car maker's and tyre manufacturer's recommendations. It is acknowledged that under certain circumstances, 'run-flat' tyres may be used in an uninflated or partially inflated state.
How Much Tread?
The legal minimum tread depth requirement for a car tyre is, 'at least 1.6mm throughout a continuous band in the centre 3/4 of the tread and around the entire circumference.' This tread depth must not fall below the legal minimum and the original tread pattern must be visible.
Must I Carry a Spare?
In law, you aren't obliged to carry a spare tyre and nor need one meet legal requirements when it is stored in or under the car. However, if a spare tyre is used, it must comply with all the above legal requirements.
The Penalties
Now for the bottom line. What will illegal tyres cost you? Read on, carefully…
If you use a vehicle with one or more defective or illegal tyres, a police officer can issue a Fixed Penalty Notice (a Conditional Offer Notice in Scotland).
At his or her discretion, a police officer may decide not to issue a Fixed Penalty Notice but may report the case for prosecution.
Both the car's driver and its owner (if he or she is not the same person) are liable. One or both may be issued a summons.
A court can impose fines up to a maximum of £2,500, and three penalty points. This relates to a car; the financial penalty for a goods vehicle or for one built or modified to carry more than eight passengers can be double this amount.
If a car has more than one defective tyre, a summons can be issued for each illegal tyre.
Under certain circumstances, disqualification becomes possible.
Sobering reading? Certainly, but this is probably less punitive than the physical costs of a car accident caused by an illegal tyre.
Article Resource
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.
Driving on worn or damaged tyres can attract a fine (or an MOT failure) and it can also place you firmly in breach of your car insurance policy's conditions. Both these events matter but something else you may be doing is of far greater importance. Never forget that using tyres that are of the wrong type, are damaged or are worn endangers lives.
Important Points
What makes a car tyre poor? Several aspects can put a tyre in this category but there are important factors you need to consider…
Car tyres must not have any lumps, bumps or tears caused by separation or partial structural failure.
They must not have a cut or tear longer than 25 millimetres, or longer than 10 per cent of the width of the tyre's section (whichever is the greater). No such damage may be sufficiently deep as to reach the tyre's internal cords.
No part of the tyre's internal plies or cords may be exposed.
Any tyre must be compatible with the type of tyres fitted to the other wheels
Any tyre, on a car or trailer, must be fit for purpose and free from any defect that might endanger any person or damage the road.
Legal Tyre Maintenance
All car tyres have to be correctly inflated, to the car maker's and tyre manufacturer's recommendations. It is acknowledged that under certain circumstances, 'run-flat' tyres may be used in an uninflated or partially inflated state.
How Much Tread?
The legal minimum tread depth requirement for a car tyre is, 'at least 1.6mm throughout a continuous band in the centre 3/4 of the tread and around the entire circumference.' This tread depth must not fall below the legal minimum and the original tread pattern must be visible.
Must I Carry a Spare?
In law, you aren't obliged to carry a spare tyre and nor need one meet legal requirements when it is stored in or under the car. However, if a spare tyre is used, it must comply with all the above legal requirements.
The Penalties
Now for the bottom line. What will illegal tyres cost you? Read on, carefully…
If you use a vehicle with one or more defective or illegal tyres, a police officer can issue a Fixed Penalty Notice (a Conditional Offer Notice in Scotland).
At his or her discretion, a police officer may decide not to issue a Fixed Penalty Notice but may report the case for prosecution.
Both the car's driver and its owner (if he or she is not the same person) are liable. One or both may be issued a summons.
A court can impose fines up to a maximum of £2,500, and three penalty points. This relates to a car; the financial penalty for a goods vehicle or for one built or modified to carry more than eight passengers can be double this amount.
If a car has more than one defective tyre, a summons can be issued for each illegal tyre.
Under certain circumstances, disqualification becomes possible.
Sobering reading? Certainly, but this is probably less punitive than the physical costs of a car accident caused by an illegal tyre.
Article Resource
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.
Tuesday, 14 June 2011
It's Quicker By Tube: Car Exhaust System Pointers
A car exhaust system usually has one important characteristic. The fact that it is capable of keeping poisonous gases safely away from the car's passengers? No. The fact that it can reduce a loud, raucous noise to a tasteful refined humming? No. The fact that it's catalytic converter can trap harmful particles and noxious gases, therefore keeping the environment cleaner? No, it's none of these. The important point is that most people only pay attention to their car's exhaust system when it goes wrong.
Sadly, the notion of the everlasting car exhaust is a mere pipedream. Looking at what a car exhaust has to put up with on a daily basis soon tells us why. Have you ever seen the flames belching from a top fuel dragster with open exhausts? Your car would do the same if it had nothing but open pipes. So from a cold start, a car exhaust system has to cope with temperatures up to about 1400 degrees Fahrenheit (760 degrees Centigrade) at full load. This happens at the exhaust manifold, under the bonnet but the increasing requirement to run engines with a weak (or lean) fuel mixture leads to an increase in car exhaust temperature. For example, if the car has a turbocharger, this can be required to run at 1050 degrees Centigrade (1922 degrees Fahrenheit). Just to give you an idea what this means, 49 degrees Centigrade will burn your skin; your blood would boil at 101 degrees.
Heat isn't all that a car exhaust has to handle repeatedly. The materials that pass through an exhaust system include nitromethane, nitric acid vapour, hydrocarbons, carbon monoxide, sulphur dioxide, particulate matter (i.e. soot and smoke), and volatile organic compounds. Many of these elements are corrosive and the presence of water as a by-product of burning petrol in the engine doesn't make life any easier for the metal of the car exhaust.
So, your car exhaust has to cope with a lot. Is this all? In a word, no. Apart from the heating and cooling cycles and the toxic contents it must deal with, a car exhaust has to cope with mechanical stresses and strains on every journey. A car exhaust is a weighty structure that, at one end, has to deal with an engine that moves about on its flexible mountings. At the other end, the exhaust has to remain fairly still, especially when its tail pipes exit through the car's rear panel. Then there are the demands of speed bumps, potholes and the like. The car exhaust, suspended on flexible mountings over its whole length, has to remain intact under what can be enormous transmitted forces.
The above, which is not overly detailed, constitutes a tall order by anybody's standards. In many respects, it is remarkable that a car exhaust will last for any length of time in the face of the demands placed on it every day. The encouraging news is that a car exhaust can usually be replaced quite quickly, at a good exhaust fitting centre.
Unsurprisingly, you can't do a great deal to give your car exhaust an easier life. You can try to ensure any journey you make is long enough to make the car exhaust hot, which will burn out damaging internal water. You can give the exhaust system a rinse when washing the car, to get rid of corrosive salt. Above all, listen to your exhaust, it'll soon let you know when it's past its use by date. Finally, remember that the 'cat' – the catalytic converter – will need replacing at least once during your car's lifespan.
Article Resource
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.
Sadly, the notion of the everlasting car exhaust is a mere pipedream. Looking at what a car exhaust has to put up with on a daily basis soon tells us why. Have you ever seen the flames belching from a top fuel dragster with open exhausts? Your car would do the same if it had nothing but open pipes. So from a cold start, a car exhaust system has to cope with temperatures up to about 1400 degrees Fahrenheit (760 degrees Centigrade) at full load. This happens at the exhaust manifold, under the bonnet but the increasing requirement to run engines with a weak (or lean) fuel mixture leads to an increase in car exhaust temperature. For example, if the car has a turbocharger, this can be required to run at 1050 degrees Centigrade (1922 degrees Fahrenheit). Just to give you an idea what this means, 49 degrees Centigrade will burn your skin; your blood would boil at 101 degrees.
Heat isn't all that a car exhaust has to handle repeatedly. The materials that pass through an exhaust system include nitromethane, nitric acid vapour, hydrocarbons, carbon monoxide, sulphur dioxide, particulate matter (i.e. soot and smoke), and volatile organic compounds. Many of these elements are corrosive and the presence of water as a by-product of burning petrol in the engine doesn't make life any easier for the metal of the car exhaust.
So, your car exhaust has to cope with a lot. Is this all? In a word, no. Apart from the heating and cooling cycles and the toxic contents it must deal with, a car exhaust has to cope with mechanical stresses and strains on every journey. A car exhaust is a weighty structure that, at one end, has to deal with an engine that moves about on its flexible mountings. At the other end, the exhaust has to remain fairly still, especially when its tail pipes exit through the car's rear panel. Then there are the demands of speed bumps, potholes and the like. The car exhaust, suspended on flexible mountings over its whole length, has to remain intact under what can be enormous transmitted forces.
The above, which is not overly detailed, constitutes a tall order by anybody's standards. In many respects, it is remarkable that a car exhaust will last for any length of time in the face of the demands placed on it every day. The encouraging news is that a car exhaust can usually be replaced quite quickly, at a good exhaust fitting centre.
Unsurprisingly, you can't do a great deal to give your car exhaust an easier life. You can try to ensure any journey you make is long enough to make the car exhaust hot, which will burn out damaging internal water. You can give the exhaust system a rinse when washing the car, to get rid of corrosive salt. Above all, listen to your exhaust, it'll soon let you know when it's past its use by date. Finally, remember that the 'cat' – the catalytic converter – will need replacing at least once during your car's lifespan.
Article Resource
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.
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