Fascinating Facts About Car Tyres

Car tyres. We tend to take them for granted and, though they aren’t fit and forget items, we tend not to invest too much time in looking after them. Provided we regularly check their pressure and physical state, car tyres generally get on with their job, quietly and efficiently. However, the following facts might open your eyes, about car tyres in general and about particular aspects concerning them.

Imagine fifty-five pence. That shiny heptagonal coin and its small circular counterpart are capital. However, the idea that you are throwing this much away with every gallon of fuel you use is a less than capital idea. Yet, running your car tyres at less than the recommended pressure can cost you 10 percent in terms of fuel economy. As under inflated tyres are harder to move along the road; they give the engine more work to do and this means more fuel is burned.

The law is an ass, said Mr. Bumble, in Charles Dickens’ ‘Oliver Twist’. He wasn’t talking about car tyres but the principle nevertheless applies. The law says that your car tyres must have no less than 1.6 millimetres of tread. Legal? Yes. Sensible? That’s arguable. A mere 1.6 millimetres of tread is generally accepted as cutting things fine. Tyre manufacturers mould two millimetre-deep tread wear indicators into tyres, with good reason. It’s arguably better to comply with the spirit of the law here rather than the letter, as the consequences of an uncontrollable skid in wet conditions cost a great deal more than new tyres.

What makes car tyres grip the road? The different types of tyre – all weather, winter, mud and snow, all terrain and performance – share common elements. The hardness or otherwise of the rubber in them and the tread pattern they have make a major difference in terms of grip, tyre life, on-road behaviour and longevity. In general though, it is the hardness (or softness) of the tyres’ compound and the water-clearing abilities of the tread that make the most difference to the level of grip given.

There’s nothing better than a new set of car tyres, is there? Some have found out to their cost that brand new tyres aren’t necessarily as grippy as their predecessors. The good news is that this relatively lessened grip doesn’t last long. If car tyres weren’t coated in an anti-stick compound during manufacture, they’d never leave the mould. This coating has to wear away before full grip is achieved. So run your new tyres in, driving more carefully for the first 500 miles or so. This is particularly important in wet conditions.

More than 40 million car tyres. That’s a lot of rubber but it is the number of tyres that are disposed of every year. Following EU directives means that comparatively few tyres go into landfill these days. Some are treated to new treads, minced tyres become carpet underlay and some wind up as part of new road surfaces. Plans are in progress to recover energy from old car tyres; they could replace coal in some industries.

Merityre are a leading UK independent supplier of car tyres. Why not visit their website at www.merityre.co.uk and see where you can buy your next set of tyres.

Beating Winter: Car Tyre Tactics For Bad Weather

It’s that time of year again. The days are short, the nights are long, precipitation is up and the mercury’s dropping. Your car’s tyres may be nearly new but there are limits to what they can do. So here are a few tips to help preserve life and limb even in the worst conditions.

There are no such things as magic tyres, despite some people’s believing that their car tyres have prestidigitatory properties. In fog, for example, your tyres won’t stop you instantly, just because you haven’t seen the line of cars up ahead in time. Equally, your tyres can’t suddenly give you enhanced grip because you need to swerve around a similar obstacle. Drive only as fast as you can see.

Rain is another condition that requires caution. Standing water in particular can be extremely dangerous. Car tyres can dispose of surprisingly large amounts of surface water. However, when there’s too much to shift, they ride on the water surface instead. This is aquaplaning; in short, it equals no grip. Drive only as fast as your tyres will allow.

Floods are an altogether different matter. Hitting a large body of water standing a third of the way across a road at speed might give you vicious steering pull but you’ll get through if you allow for this. In deep water, your car tyres will cope admirably but your car might not. Many cars nowadays have a low-mounted air intake. If this inhales water, the engine will be wrecked. Don’t enter floodwater unless you’re certain of its depth. Keep to the crown of the road where the water will be shallowest. Keep the engine revving, to prevent water entering the exhaust and drive slowly – you have a car, not a boat. If in any doubt at all, find another route.

Snow and ice and car tyres don’t always mix. Winter tyres are a boon and it’s worth considering acquiring a set, especially if you live somewhere that experiences these conditions regularly. The usual, all-round car tyres can’t get a grip on ice and snow, even if they’re gracing a 4X4. When conditions are really bad, you may need to consider some additional hardware. ‘Snow socks’ are a new idea. These tough, woven tyre covers are easy to fit, quiet and grippy. However, they don’t last long on tarmac. The alternative is snow chains; not so easy to fit but far tougher, if noisy.

Above all, winter driving requires caution. Grip is always compromised to some extent and if you try to drive normally, losing control becomes a very real possibility. Remember also that your vision is likely to be compromised as well. Remove snow or ice from your car’s glass before moving an inch and always think about stopping distances. Modern electronic aids, such as traction control and anti-lock braking systems help but they’re no more magic than car tyres are. Should the worst come to the worst, and vision and grip both come under the general heading of appalling, you don’t have a choice. Stay at home!

Merityre are a leading UK independent supplier of car tyres. Why not visit their website at www.merityre.co.uk and see where you can buy your next set of tyres.

Baywatch: What Makes A Good Car Tyre Bay?

We’ve all driven past them. Tyre bays might offer the best prices, two car tyres for the price of one, special deals on four-tyre sets and all manner of other tempting offers. This is, of course, just advertising and, as Joseph E Levine said, “You can fool all the people all the time if the advertising is right and the budget is big enough.” Now, it’s true that car tyres are often a distress purchase but even so, knowing what makes is good tyre bay is knowledge worth having.

So, what makes a good tyre bay? The answer is a two-word one: products and services. Here, it is not only the range of products and services but their quality that matters. Here’s what to look for in your car tyre-buying expeditions.

It’s obvious that a tyre bay is there to sell you car tyres. What you need to know first is whether the tyre bay is going to sell you new tyres. If you can, take a look at the stock on the shelves – you’re looking for the DOT codes. If this has three digits, walk away – four-digit codes came in after the year 2000. The way to read a four-digit code is easy to understand. The first two figures represent a particular week in the year denoted by the last two figures. So, a tyre marked 5009 was made very near the end of 2009. Car tyres have a six-year shelf life – and you can always check the tyres’ age before they’re fitted.

Speaking of tyre fitting, tyre bays have this down to a fine art. Given that car wheels and tyres live in a grimy environment, some grubbiness is acceptable even in a good tyre bay. However, untidiness should be frowned upon. If the tool cabinets are well organised, they’re liable to be well equipped. Similarly, tidy floors and a lack of overflowing bins and dead tyres underfoot denote an efficient workshop.

Wheel alignment is a service offered by many tyre bays. The days of the old Dunlop optical alignment gauge, effective though it was, are long gone. If you see computerised, four-wheel geometry wheel alignment, maybe with the involvement of measurement using lasers, you can rest assured that you’re in a good tyre bay. Remember that poor wheel alignment is a car-tyre eater.

Much the same goes for wheel balancing, which is an essential part of tyre fitting. On unbalanced tyre/wheel combinations, car tyres work less well and wear out faster. In the (very) old days, a balancing kit that involved sitting a wheel and tyre on top of a milk bottle was touted. Computerised wheel balancing is the norm nowadays – accept nothing less.

Many tyre bays are no longer transfixed, work-wise. Putting the tyre fitting and wheel balancing machinery into a van, along with an air compressor, equals mobile tyre fitting. You may take advantage of this service and some tyre bays offer a ‘call and inspect’ service, particularly for car fleet operators.

While there are other services offered by tyre bays, such as air-conditioning checks, the above suggest that a tyre bay offering these goods and services is up-to-date as well as on the ball. This in turn suggests that one very important element of tyre supply and fitment will be available and reliable. Never forget that the staff in a good tyre bay can advise you about choosing the best car tyres for your needs.

Merityre are a leading UK independent supplier of car tyres. Why not visit their website at www.merityre.co.uk and see where you can buy your next set of tyres.

Protection Racket: Locking Wheel Nuts Keep Car Tyres Safe

There are certain, indisputable facts in life. One is that car tyres – and car wheels – are expensive. Consequently, the, er, light-fingered among us have been known to lift our wheels and tyres, by first lifting our cars on to a convenient pile of bricks. In the relatively recent past, car alarms have become smart enough to detect when a car is being jacked up and they can tell everyone in the vicinity all about it. This is ‘active security’, which is a subject in itself. In this article, we’ll look at an example of ‘passive security’.

Passive security needs no power source: it is a barrier rather than a whistle-blower. All it need do is be there to be effective. Sometimes, passive security devices are evidently present. However, devices that mechanically prevent car wheels – and car tyres – from being stolen, tend not to shout about it. The thieving fraternity knows what locking wheel nuts or bolts are about and it’s rare for a vehicle to lack them nowadays.

How, then, do these devices work? Their operation really couldn’t be simpler. If you attach your car wheels to your car’s hubs with four or five nuts or bolts apiece, and those nuts or bolts have a hexagon head, the danger is obvious. Replace one fastening per wheel with a fastener that needs a key of some sort to permit it to be removed and the solution is present and evident. Your wheels and your car tyres are as safe as they can be made.

The obvious question that arises is about the key itself. This, rather than being a key as such, is usually an adaptor, which allows a wheel nut/bolt spanner to be used to remove the special fastening it fits. So, what to do with the key, or adaptor? Most people keep it in the boot, or perhaps in the car’s glove box. This means your car tyres and wheels are protected by the car’s alarm. This could be worse, of course, and what is relevant is that you never know when a car tyre needs to be changed. The only watchword exists when you have to leave your car unattended for a while, say in an airport car park. Having seen a BMW on bricks and wearing no wheels, I can safely suggest that if the wheel key had been in Spain or France with the car’s owner, the wheels and tyres would probably have been present when the car’s owner returned.

The locking of car wheels and tyres has been refined to the extent that corrosion and wheel balancing problems are a thing of the past. There are some cheap sets of locking wheel nuts/bolts on the market; these can fail even when used properly, so avoid them. Nevertheless, another question arises: what happens if you’ve lost the key to an unarguably tough locking wheel nut or bolt? One person on the Internet resorted to using a power hacksaw to dismantle the offending wheel and tyre. However, radical resection isn’t really necessary. Car tyre fitters have generally encountered this problem before, and keep a range of tools, at least one specifically designed for this task.

Merityre are a leading UK independent supplier of car tyres. Why not visit their website at www.merityre.co.uk and see where you can buy your next set of tyres.

More Star Cars - Movie Flyers, On Tyres

The star cars that make some movies memorable often start life as completely standard vehicles. They rarely stay that way and they always attract a following. So let us follow in the tyre tracks of some Hollywood luminaries.

Our first diva was in fact six cars, of which four still exist. In many respects it was ahead of its time; by the end of the first movie in which it appeared, it was running on rubbish. This early green machine, Doc Emmet Brown’s time-travelling car was a DeLorean DMC12 and it first burst on to our movie screens in 1985. A trilogy of movies and many years later, Christopher Lloyd (Doc Brown) is 71, and Michael J. Fox (Marty McFly) is 49, has Parkinson's disease and an honorary doctorate from the Karolinska Instituet. Of the four DeLoreans remaining, two are studio tour stars at Universal, one lives on the ceiling of Planet Hollywood in Honolulu - and the last one is being restored. Some of the cars that John Z. Delorean made still set tyres to tarmac, and some among their number have attained a degree of immortality.

'So cool it hurt' is an epithet that applied to the late Steve McQueen, and his handling of the 1968 Ford Mustang GT390 Fastback he used in 'Bullitt' did his reputation no harm at all.

During the seven-minute, tyre-burning chase sequence with the baddies' Dodge Charger R/T440, McQueen did most of the driving and there was no camera trickery. Both the Mustangs used were given tuning tweaks so they could keep up with the more powerful Magnum Chargers, and one of each was given beefed-up suspension and a full roll cage.

All that drifting car tyre smoke was real, as was much of the San Francisco traffic. One thing, however, was a later addition. The full-blast V8 engine sounds came from an example of the GT40, Ford's four-times Le Mans winning racing car.

Now for a quirky one. What has massive tyres, ten carburettors with gold plated intake pipes, and a huge, Ford Cobra motor? Need more clues? How about Jahns high-domed pistons and an Iskendarian camshaft? Still too techy? Ok then.

Customizer George Barris built the idiosyncratic vehicle in question. It was based on a lengthened 1923 Model T ford chassis and had a custom body. Still struggling? Alright, here are some names. The car was featured in a 1960s TV comedy starring Fred Gwynne, Yvonne De Carlo; Al Lewis played Grandpa. Those who are thinking of Clive Dunn at this stage can go to dunce's corner right now. However, the names Herman and Lily might ring some bells. Yes, it's the Munster’s Koach.

This unique car toured the 'States extensively in the 1970s, and pre-tour, George 'Batmobile' Barris gave it a new paint job. The car now rests in peace, in the 'Cars of the Stars' museum, in Keswick, Cumbria.

Finally, a vehicle with just 114 horsepower from its 4.9-litre, six-cylinder engine is hardly likely to set tyres or tarmac alight, especially with its three-speed automatic transmission. However, the very same vehicle had its charm and made us laugh, even if it was slow. The film 'Dumb and Dumber' featured this 1984 Ford Econoline van, complete with floppy, furry ears, a lolling tongue and a full fur coat. Jim Carrey and Jeff Daniels' 'Mutt Cuts' van didn't stay long but the movie wouldn't have been the same without it!

Merityre are a leading UK independent supplier of car tyres. Why not visit their website at www.merityre.co.uk and see where you can buy your next set of tyres.

Car Tyre Clearance: Making Sure Your Wheels Measure Up

There’s nothing in the rule book that says you must keep the wheels your car had on when it arrived. Many people change their wheels, for a variety of reasons. Some want a different style of wheels, some want wider wheels and most want alloy wheels. A change of wheels usually means a change of car tyres. That is no problem in itself but there is a trap into which a lot of people have fallen with a resounding clatter.

The thing is, any car wheel will accept one or more different sizes of car tyre. There is, however, more to car wheels than just rim diameter and width. Ignore the other measurements or get them wrong and disaster looms. In short, you can find there’s a clash between your car tyres and its bodywork. This can happen with steering or suspension movement and often, it happens just the once, immedately before the tyre and bodywork wreck one another.

The first measurment is Pitch Circle Diameter, or PCD for short. This is nothing to do with car tyre to bodywork clearance but if you get this wrong, the wheels won’t fit. The PCD is the diameter of a circle drawn through the centre of your wheel mountings, be they studs or bolts. The wheels obviously need the right number of stud or bolt holes but you also need to ensure that the wheel nuts or bolts have the right thread and profile for your car’s hubs, and that they are correct for use with the wheels you’re using.

Now for the easy ones: rim width and diameter. You could go for the standard measurements here. However, many people want bigger wheels and low profile tyres. Fair enough – just ask the wheel supplier, who you can always blame if something doesn’t fit. It’s also important to make sure that the wheels can accommodate your brakes. Big wheels and low profile tyres were invented, in part at least, to allow for bigger brakes to be crammed in. These days, clearances are close and it’s problematic if your wheels and disc calipers rub each other. This makes only one difference to the car tyres: they won’t work too well if the wheels can’t rotate.

So, we come to the tricky one, the knotty problem of wheel offset. This is most easily understood with a little bit of theory. Imagine a car wheel sawn in half across its diameter. If you were to draw a line through the centre of the wheel rim, and this line was to coincide with the wheel’s hub mounting face, the wheel offset would be zero. If, as is common, the hub face lies outboard of the centre line, the wheel has positive offset. Conversely, if the hub face lies inboard of the centreline, the offset is negative. The degree of offset, apart from altering wheel clearance, has a profound effect on the behaviour of your car tyres.

Visually, positive offset places the car tyre further under the car’s wheelarch. Negative offset makes the tyre carcass sit further outboard. In either case, provided you don’t choose a seriously large figure in relation to what is standard, the car tyres won’t cause difficuties. That said, there is a danger in choosing too radical an offset, as this figure (usually expressed in millimetres) affects steering. You could find that your steering has becomes mysteriously heavy. Worse still, you could find it’s become over-light, to the extent that straight line driving becomes a thing of the past.

Merityre are a leading UK independent supplier of car tyres. Why not visit their website at www.merityre.co.uk and see where you can buy your next set of tyres.

Car Tyres Teasers - Important Facts You May Not Know

‘We’re on your side.’ This sounds like the tag line in an advertisement but here it refers to the codes on a car tyre’s sidewall. Most of us know the obvious ones like those referring to wheel diameter and tyre section. There are, however, many other pieces of vital information to be found, moulded into the sidewall. Let’s consider some of the more important ones.

Did you know that some car tyres have a marked rating that indicates how well they handle heat build up? If you see a mysterious “A” on a tyre, it has the highest rating. A “C” denotes the lowest.

The traction rating shows how well a tyre can stop you on a wet road. This rating goes from “AA” to “CC”. No prizes for guessing which is the best.

Now for some numbers. Tread wear ratings go from 60 to 600 in increments of 20 and the figure shows how long the tyre is expected to last. In theory, a tyre marked “200″ should last twice as long as one marked “100″. This is, however, a relative rating. The actual tyre life will depend on many factors, including your driving style, the road surfaces encountered, correct wheel alignment and the right tyre pressure. Think ‘benchmark.’

The speed rating a tyre carries is extremely important. Using over-specified tyres is a (very expensive) upside here; tyres for high-speed use can be used at lower speeds. On the other hand, if the speed rating is too low and you have an accident, your insurance company may take a dim view of the tyres your car was wearing at the time. Speed ratings run from “L” (75 mph) to “Z” (150 + mph). Currently, H-rated tyres (130 mph) hold the largest percentage of new tyre sales.

So much for speed, what about load? Yes, car tyres tell you about the load they are capable of carrying, They have a marked load index (LI), which is valid for sub-130 mph speeds. Load indices range from 50 (190 Kg) to 169 (5,800 Kg) but the calculations are a touch complex. Let’s say you have a car that weighs 2 tonnes, or 2,000Kg. Divide this by four to get the weight on each wheel; this equals 500Kg. So far so good, but, do you know that all four wheels carry 500Kg or is one end of the car heavier than the other? In practice, it’s usual to add a percentage to cover such factors.

In our example, then, the car needs tyres with a load index of 84. We can add 20 percent, giving a weight bearing capacity of 600Kg. Therefore tyres with a load index of 90 will do very nicely. In reality, a car tyre’s load rating will exceed its actual needs by a long way. However, when speeds reach 130 mph or more, the load index calculations change dramatically. For reasons far to technical to explain here, the theoretical load rating decreases as road speed rises. In the event you run a very, very fast and heavy car where the speed cameras don’t work, there are experts in such matters. Find one!

Lastly, you should never use a tyre more than 6 years old. The date of manufacture is part of the DOT code marked on one sidewall. For example, a tyre marked “2709″ was made in the 27th week of 2009.

Merityre are a leading UK independent supplier of car tyres. Why not visit their website at www.merityre.co.uk and see where you can buy your next set of tyres.