Save Money on Fuel by Checking Your Tyre Pressures!

Did you know that having under-inflated tyres affects the handling and grip of your vehicle which can cause it to behave in an irregular or unpredictable way? Furthermore it means that you have a much higher chance of suffering a dangerous blowout, especially on long distance high speed journeys. The tread on your tyres will also wear unevenly if it is over or under inflated and you will need to have them replaced more often.

 By keeping your tyres at the correct pressure your running costs will be reduced as you will save money on fuel. Under inflated tyres require more force to make them turn, and therefore… more fuel.

So… Where do you find the correct tyre pressure for your vehicle? Well there are a number of places to check this. Your vehicle user manual is usually a good place to start as this should also provide information on how much extra pressure you need if you are carrying a heavy load/trailer or if you are going to be travelling at a high speed for a long time.

 Other places it may be are on a label on the front door posts of your car, or on the back of the fuel cap cover. You can also check online at www.tyresafe.org/tyre-safety/tyre-pressure-check.

Now that you know the right pressure for your tyres you need to check that they are correct. To do this you will need some form of tyre pressure gauge like a foot pump or a digital pressure reader (all available at your local car parts store). Remove the dust cover on your valve and attach the gauge.

If your tyres are over inflated…

·         Let some air out by pressing the core of the valve in using a match (or something similar).

·         Deflate the tyre in short bursts and check regularly to ensure you don’t let too much out.

If your tyres are under inflated…

·         Ideally you should inflate your tyres when they are cold as a warm tyre can increase in pressure by 2psi (pounds per square inch).

·         Use a foot pump, plug in a 12v inflator, or use your local fuel stations tyre pressure inflator (these should have charts with all vehicle tyre pressures on them).

Make sure you check all of your tyres, including the spare! Once your tyres are inflated to the correct pressure, put the dust cap back on and you should be ready to go!

At all of our Merityre branches we offer Nitrogen Inflation. By filling your tyres with Nitrogen, they will maintain their correct pressure for longer as Nitrogen doesn’t leak through the tyre’s structure. Normal compressed air consists of mostly oxygen and water vapour, both of which permeate through the tyre casing. By filling your tyres with Nitrogen you will get:

·         Better road holding

·         Longer tread life – up to 25% increase

·         Reduced fuel consumption – Up to 5% reduction

·         No corrosion to the inside of the wheel.

 

You should check your tyre pressures at least once a month, before you go on long journeys, or whenever your vehicle is carrying heavy loads. If you are unsure of anything or would like help, bring your vehicle to your local Merityre branch http://www.merityre.co.uk/find_a_centre.htm and we’ll be happy to do it for you, completely free of charge. 

Checking your tyres… what.. why.. when.. and how…??

WHAT…

So.. How many of you actually know what you’re looking for when you check your tyres? I’ll be the first to admit that before I started working at Merityre I had no idea that the tread on your tyre could wear unevenly, or that you could actually repair a puncture rather than having to buy a brand new tyre. Well in this entry I will try to explain exactly what to look for when you check your tyres.

WHY…

It should go without saying that your tyres are a fundamental part of your vehicle as they are the only parts which have contact with the road (hopefully)!! It is therefore incredibly important that your tyres are in a safe and working condition when driving yourself/friends/family or anyone else around. You never know how many times your tyres may have saved you and your vehicle from serious accidents or damage already.

Did you know that WORN TYRES:

·         Are unsafe

·         Do not give you the adhesion to stay safe on the road

·         Can be illegal… Penalty points here we come

·         Can burst, leading to serious accidents

·         Increase fuel consumption!

·         Pick up foreign objects more easily which can lead to punctures

·         Can lead to other more serious problems with your car

·         Can increase the possibility of prosecution after an accident and increase insurance premiums.

·         Will give you an uncomfortable ride

WHEN…

So firstly, when should you check your tyres? Well there isn’t really a set amount of time between when you should do checks, but we would recommend every week, and before undertaking any long journeys. This means that if you do have any problems, you will spot them quickly and hopefully avoid driving around on potentially dangerous tyres.

HOW…

The first step is to turn on your engine (with the handbrake on and out of gear), and turn the steering wheel so it locks on one side, then turn the engine off again (this will depend if your vehicle has power steering). This allows you to see the full breadth of the tread on your front tyres which is important as it allows you to notice if there is any uneven wear across the tyre.

(Many modern vehicle tyres are very wide and the innermost edge of these can wear right down while the outside edge can appear faultless. This can also occur on tyres if the steering and suspension alignment is out on the vehicle. It is very important to check the full width of the tread!)

LOOK FOR…

·         Now you check your tread depth. The easiest way to do this is using a tread depth gauge, but if you don’t have one of these you can use the tread wear indicators which are located within the grooves of the treaded part of the tyre. These are small raised blocks about 10mm in length and 2mm in height which are situated all around the tyre (so you should be able to find them). The legal limit for tread depth is 1.6mm and the indicators are raised to 1.6mm to 2mm. Therefore if any part of the tread area is running flush with the indicators, your tyre has worn to its lowest level and needs replacing.

 

·         You need to make sure that you check as much of the circumference of the tyre as possible as sometimes one section of the tread will be fine, and another section will be worn. This may mean that the tyre is distorted. You need to check for any material degradation in the tyre, for example cracking and perishing.  At the same time look for any deep or long cuts and any foreign objects. Your car drives over lots of different surfaces so you may see bits of stones here and there, but any object which does not come out easily may have penetrated the tyre and be causing pressure loss (puncture).

 

·         Now have a look at the side walls of the tyres. The side walls are prone to damage from impacts, chafing against curbs, under inflation and tearing. You will be looking for cuts, abrasions or missing rubber. When a tyre has a puncture or has been run under inflated for a while it can cause pinching between the wheel and the road surface (run flat damage). This can be seen as an abrasion mark running the entire circumference and worn letters and numbers on the side walls. When this occurs your tyre will need replacing.

 

·         Bulges can be detected by running the flat of your hand over the entire surface of your sidewall. A bulge represents serious damage to the structural integrity of the tyre.

 

·         In the outer rim of the wheel you will find the valve. Check this carefully for any deterioration of the material. Ensure caps are fitted. By moving the valve stem from side to side, look for cracking of the rubber around the base.

Repeat all of these processes for each tyre and don’t forget the spare!

So, for a quick recap:

Your tyres need attention if they have:

·         Low tread depth

·         Deterioration of the rubber (cracking or perishing)

·         Uneven tread wear (distortion of tyre)

·         Deep cuts or sections of tread missing

·         Embedded foreign objects

·         Side wall damage and bulges

·         Damaged or worn valves

So.. Now you know why it is so important to check your tyres, and not just the tread depth, but the whole tyre. If you find this all a bit too much, then just bring your car to your local Merityre Branch www.merityre.co.uk/find_a_centre.htm and we’ll do it for you absolutely free. We will also give you advice on when you may need new tyres and give you a Merityre Tyre Check Report on their condition. You can also have a FREE Wheel Alignment check which will show up any problems and help to prevent your tyres from wearing unevenly.

For information about our Club Card Plus, go to our website at www.merityre.co.uk or ask at your local branch.

The next entry will explain how to check tyre pressures.

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Car Tyre Science. Dynamic Performance

Car tyres are often taken for granted. You turn the steering wheel, your car takes the corner, you press the brake, your car stops. This is fine but knowing how car tyres work and the characteristics they generate in terms of handling and roadholding is both interesting and potentially helpful to your driving.

Every car tyre has an area of tread, about the size of an adult’s footprint, in contact with the road surface. This is called, somewhat predictably, its contact patch. Imagine the tyres’ four contact patches travelling along a road in a straight line. These four areas of tread are what keep your car on the road, allowing you to accelerate, steer and brake with confidence.

Now, what happens to car tyres in corners? Imagine the wheels following the arc that the corner represents. The wheels will be following the arc faithfully, but there’s a hidden force at work. Imagine you’re Superman and have X-ray vision. Looking down at the top of a wheel and tyre combination, you’d see that the contact patch will be following a tighter curve than the wheel is following.

So, what’s happening? Why the difference? It’s there because sideways force put on the tyre by the weight of the car is deforming the car tyre’s carcass. Now, imagine a straight line drawn through the centre of the wheel and another drawn through the centre of the contact patch. There will be a difference between the two – this difference is called the slip angle.

As slip angles increase, the car tyre’s grip increases, up to a point. When the forces involved head towards the maximum level of grip the car tyres offer, one of three states will apply. Say the slip angles are equal at both ends of the car. In this case, the grip at each end of the car will be the same. When the grip level’s limit is reached, the car will go into a classic, four-wheel drift. The car’s handling will be ‘neutral’. Racing cars are set up to give neutral handling.

Supposing the slip angles of the car tyres at the front are greater than those at the rear. Then, the driver will need to apply more steering input to make the car follow the chosen curve. This is called ‘understeer’.

When it reaches the limit of effective grip of its car tyres, an understeering car will slide off the track forwards – it simply won’t be able to corner tightly enough. In practice, most road cars understeer. Why? Because understeer is a generally controllable condition – it’ll help scrub off excess speed when a corner is taken too enthusiastically.

The third state occurs when the rear car tyres’ slip angles are greater than those of the front tyres. The rear tyres will be giving less grip than the front ones. At the limit, the car’s tail will slide towards the outside of the curve. When you see a Formula One car or Touring Car spin off a track, it’s gone beyond oversteer.

This explanation is necessarily basic. In fact, very many parameters affect how car tyres respond to the forces imposed upon them. However, the physics are just as basic, and give car designers benchmarks from which to work.

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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.

Super Savers. Keeping Car Tyre Costs Down

Depressing as it may be, the tottering economic situation, in this country and across much of the world, is a fact. This means we must live with it but we needn’t merely accept it passively. We can take active steps to keep costs down, and in regard to our motoring and especially our car tyres, there are plenty of tips and tricks for saving money.

Efficiency Counts

The deductive powers of a Sherlock Holmes aren’t needed to figure out where car tyre factors could be costing us money. The key word is ‘efficiency’, and here’s how inefficiency can affect motoring costs.

All cars give a certain power output. Whether this is quoted in kilowatts, pferdestärke or good old horsepower is irrelevant, power can be wasted by inefficiency. A certain amount of power is required to make a car progress, and anything that impedes this progression is wasteful. Under inflated car tyres require more power to make progress, because the lesser tyre pressure increases their rolling resistance. Run your car tyres at the correct pressure, or even a little higher, and you’ll soon see rewards at the fuel pump.

Of course, it isn’t just car tyres that can cause drag, which in turn increases fuel consumption. The current warm weather makes it tempting to use the car’s air conditioning. Would you use it so readily if you knew it could worsen your car’s fuel consumption by up to 11 per cent? You could open some windows, but this creates aerodynamic drag – it seems you can’t win. In fact, it makes sense to cool the car interior by opening the windows at slower speeds. When motoring at 40mph or over, use the aircon – it costs less.

Weight Issues

All car tyres create some drag, that’s also a fact. All car tyres also carry weight, and it’s a fact that the amount they carry can be trimmed, in some cases radically. What you carry on a regular basis in your car depends largely on how you use your car. That said, a lot of people carry unnecessary objects in the car at all times. You could argue that you really need your Wellington boots, snow shovel, overcoat and Thermos flask on board. Well, argue away – you’re carrying what represents dead weight for August and it’s you who are buying the fuel. A combination of ruthlessness and good sense about what lives in the car and when isn’t hard to apply.

Similar thinking should apply to your car’s roof rack or roof box. Sure, it’s well away from your car tyres but what’s on the roof costs you fuel simply by being their. Each has a weight, which you’re paying to transport. Each has a degree of air resistance, even if your roof box has sexy, aerodynamic styling. Again, you’re paying to push that roof-mounted deadweight through the air. Remove it when not in use and your pocket will thank you.

Obvious Strategies

There are a more fuel wasters than car tyre rolling resistance. Driving too hard and/or too fast when you needn’t are money guzzlers, as are speed camera fines and the increased insurance cost of points on your licence. Use the most efficient route, use the highest possible gear and above all, use your head. Everything in this article comes under a single heading, common sense.

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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.

Cat Show. All About A Car Exhaust’s Cleaning Component

On petrol cars, a catalytic convertor has become a standard part of the car exhaust. Catalytic convertors – ‘cats’ for short – originated in America. Like many other items, cats soon went transatlantic and later made their way into European legislation. Unsurprisingly, they wound up in the UK.

Let’s begin with the nuts and bolts of the matter. In chemistry, a ‘catalyst’ is a substance that causes or accelerates a chemical reaction without itself being affected. Fair enough but what has this to do with car exhausts? Still talking at nuts-and-bolts level, a catalytic converter is a device that uses a catalyst to convert three harmful compounds in car exhaust gases into harmless chemicals.

Again, fair enough but what are these three compounds that are so harmful? They are to be found in the exhaust gas of any petrol car and consist of…

Hydrocarbons (incompletely burnt fuel)

Carbon Monoxide (formed when petrol burns)

Nitrogen Oxides (made by combustion heat making atmospheric nitrogen combine with oxygen.)

So, just how scary are these components in car exhaust gases? Carbon Monoxide, a.k.a. CO, is the nastiest one, being poisonous to any organism that breathes air. Nitrogen oxides (NO2) lead to the formation of both smog and acid rain. Relatively innocent Hydrocarbons (HC) just produce smog but are particulate matter, which makes matters worse.

A catalytic convertor, looking rather like a silencer, forms part of a car exhaust system. The catalyst used is liable to consist of precious metals such as rhodium, platinum and palladium. These coat a ceramic honeycomb or ceramic beads inside the ‘cat’. Carbon monoxide is converted into the less harmful carbon dioxide (CO2) and hydrocarbons are converted into carbon dioxide (CO2) and water (H2O). As for the nitrogen oxides, these are converted back into nitrogen and oxygen.

Though they don’t have moving parts, ‘cats’ can suffer malfunctions. If the catalytic convertor in a car exhaust stops working, you won’t necessarily know about this until your next MOT test. A failed cat may just be worn out or its substrate (the metal-coated pellets or ceramic honeycomb inside) may have broken down. Your car may run perfectly well – it just won’t be able to pass the emissions test part of an MOT.

Often, diagnosing what’s awry with the cat in a car exhaust is tricky. If something has gone wrong with the car’s fuel system and it allows raw fuel into the cat, the unit will run red hot. This is usually pretty easy to detect, which is just as well, as the substrate can shatter at such temperatures. Fouled sparking plugs, incorrect ignition timing and failure of the engine’s air pump and/or check valve can also cause overfuelling.

Should the cat’s innards go into meltdown, or shatter through thermal shock or overheating, the result will mimic a blocked car exhaust. A sluggish throttle response is the major clue. Modern electronics mean that a fault light will flash to verify there’s a problem but detecting exactly what the problem is likely to involve diagnostics – on a laptop computer. In any event, should the problem lie within the ‘cat’, a good tyre and exhaust bay will be able to offer you a replacement unit.

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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.

Tyres On Trial

Suppose you were regularly wearing out a set of tyres on your Mini Cooper in three miles. You’d certainly be doing something very wrong, wouldn’t you? However, this is the usual car tyre mileage on one of The Russ Swift Mini Display Team’s Coopers and Russ is doing something very right – in the eyes of his sponsors and spectators, that is.

The Team, part of Russ Swift Driving Services, was formed in 1981. Current British Autotest champion and England Autotest Team Captain Russ had often been asked to demonstrate his incredible, tyre-testing car control skills. He realised a gap existed in the marketplace and contrived to fill it.

In 1987, an advertising agency saw a video of Russ at work. This led to the renowned Montego “Car Park” commercial. Though this was aired in the UK for just six weeks, the squeal of tortured car tyres was heard when the performance was featured at the Cannes Film Festival. It was also voted by American judges as the world’s most imaginative car commercial.

Where did Russ go from there? A long, long way. Eight thousand tyre-munching displays in more than 50 countries and three Guinness world records (Parallel parking in the tightest space, J Turn in the tightest space and the fastest donuts) form just a small part of his CV.

Russ and Minis go back a long way too, starting with four British Autotest Championship wins and an International Rally win in Sweden in the early eighties, in a Cooper S. More recently, Russ was involved in promoting the remake of ‘The Italian Job’, performing at premieres in London and New York. He fulfils an advisory role with many police, military, royal and diplomatic drivers, also working closely with RoSPA, the IAM and various other road safety bodies to promote safe driving. A versatile player on the car world’s stage, Russ is committed to ensuring that it is only car tyres that suffer!

The tools of Russ’s trade are largely unmodified cars. Russ uses a Mini Cooper S, standard apart from a “piece of tape on the handbrake button”. Another Mini Cooper has one other mod – a locked differential – to allow for driving on two wheels (this is the one that gets 3 miles per set of tyres – should that be per pair?). Typically, a further Mini Cooper is used (all these are BMW MINIs). Often, an MR RS Mitsubishi Evolution undertakes power slides and donuts.

A typical show features reverse spins at 40mph, parking in a slot between two cars parked side by side, using only the handbrake. Similarly, ‘parallel parking’ involves a handbrake turn into the gap between two cars parked as though at the kerbside. Then there is a ‘dance routine’ to music, involving two cars and a ramp. This last – the ramp – is used for the business of getting the locked-diff Cooper up on two tyres. The show features music and commentary – and audience participation is encouraged. The tyres may be red hot but the invited passengers have been known to end up on the pale side!

Find out more – and see pictures and videos – at www.russswift.co.uk.

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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.

Buyer Beware: How To Buy A Used Car

For many people, a car is the second most expensive purchase they make. Buying the right car can be easy but it's just as easy to encounter expensive pitfalls, especially when buying used. You need to check on everything, from the car tyres upwards and here are some pointers to help you.

Start by making sure you are looking at the right kind of car for your needs. No matter how much you may want to, you won't fit a family of four in a two-seater sports car. Most people don't make such an obvious error but many buy a car that's too big for their garage, too thirsty for their wallet or too expensive to maintain. All cars have tyres, not all have the ability to be run on a shoestring – and you'll always lose if you have to sell.

Lets assume you've found a car. What next? You have to be certain that the car matches the claims made about it. Checking the VIN (Vehicle Identification Number) is a primary requirement. Does it match the number in the V5 document? If it doesn't or isn't clearly stamped, without any evidence of tampering, the car could be stolen, a 'ringer', or the result of two write-offs welded together.
If the VIN is good, does the history add up? We're talking paperwork here, as well as the state of the car itself. Good car tyres, not to mention shiny paintwork and a ludicrously low mileage are of little value if the mileage figures in the previous MOT certificates don't tally. No MOT certificates? This is your cue to walk away.

Much the same goes for service history, which usually has a record of miles covered in it. If the car has in fact been serviced as it should have been, preferably by an approved dealership, which has entered the details into the service record, the car's beginning to look like a good buy. If every last invoice for what has been spent is present and correct, so much the better. This may include receipts for new tyres, an exhaust, a battery and any accessories.

If buying from a car dealer, a genuine HPI certificate must be provided by law. If buying from a private individual, you can arrange to have an HPI inspection. An HPI check validates the car's history and will reveal any shady elements in its past. Remember that, if buying privately, you will buy a car 'as seen'. This means that you can set tyres to tarmac quite happily but if the engine grenades on the way home, it's your problem. There is no recourse in a private sale.

When looking at the car, be very, very critical indeed. If it has been repaired and the repairs have been professionally done, that's fine. If you see badly-matching paint, poor panel gaps, scuffed tyres and ripply surfaces, the car has been badly repaired. Under the bonnet, look out for oil leaks, corrosion, fluid stains and amateur fixes. Pull out the dipstick and look at the oil. Is it black and treacly? Look elsewhere.

Car tyres can be excellent tell tales, as can the wheels that carry them. Uneven tyre wear suggests suspension misalignment at best, damage at worst. Tyres with 3 millimetres or less of tread need replacing, which won't cost the seller a penny. The same goes for cracked tyres or ones with lumps or bulges. Alloy wheels that have been badly kerbed will show significant damage, and say a lot about how the car has been driven.

Finally, remember these golden rules. One: you can always find a rival example of the car you're examining. Two: it’s a buyer’s market; you can always walk away. Three: always buy with your head, rather than your heart!

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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.