Tyres and safety

Posted on November 29th, 2013 by GEM Motoring Assist

Tyres may not be the most glamorous of components but those four hoops of rubber are the only contact between your vehicle and the tarmac.

Your car may have the most advanced electronic anti-skid system but modern safety aids are only effective if your tyres are in good condition.Modern tyres are the result of many years’ development and all have different characteristics that affect handling, ride quality and even fuel consumption. The consequence is a bewildering range of tyres on the market which can make an informed choice difficult. For everyday use, it is worth staying with the original specification tyre recommended by the vehicle manufacturer although experience and budget usually dictates the final brand choice.

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Buying tyres
Prices are never fixed either and some well-known tyre brands can be cheaper than their budget counterparts, especially from large tyre fitting centres. Bulk buying is the key and, other than shopping round, it is worth negotiating an additional discount if you need more than two tyres. However, check the quoted price includes fitting and VAT.

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Longer-lasting tread
Tyre life can vary dramatically between brands due to harder or softer rubber compounds being used. However, a car that is driven aggressively, with badly aligned suspension, may destroy a tyre in less than 1,000 miles. Conversely, a vehicle driven sedately in good condition may manage more than 30,000 miles.

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The law and your responsibilities
As tyres are so safety critical, the law is very specific about what is acceptable for road use. The Road Vehicles (constructions and use) Act 1986 has four regulations (sections 24-27) dedicated solely to tyres.

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Minimum tread
Driving a vehicle (including trailers and caravans) up to 3,500kg gross vehicle weight, with less than 1.6mm of tread across the centre 75% of the width of the tread, is an offence because less tread means less grip, which could result in a skid. If driving abroad, check the local legislation as some European countries insist on a greater tread depth.

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Regulation 27 states that any tyre must be inflated to make it fit for purpose, but it does not indicate what constitutes over or under inflation. To be certain, check that the tyres are inflated to the required pressure (found in the vehicle’s handbook) when the tyres are cold. A good time is in the morning after the vehicle has stood overnight.

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Sidewall damage
Sidewall damage is usually caused by “kerbing” (in other words, when your car comes into contact with a kerb that’s too high) and can harm the tyre internally without giving any visual clues and also affect the suspension alignment (or “tracking”) that will increase tyre wear. Any cuts found on the tyre in excess of 25mm on the outside of the tyre are also illegal. For older cars, trailers or caravans that stand idle for long periods of time, the sidewalls can perish due to sun and age degradation so check thoroughly and consider renewing any tyre that is suspect or over ten years old. It is worth supporting the vehicle using axle stands (never bricks that could collapse) to prevent the tyres from going out of shape.

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Classic cars: safety point
Classic car owners must also be aware that it is illegal to mix tyres of cross-ply, belted and radial ply construction, not only on the same axle but also on front and rear.

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Q: Can I buy part-worn tyres?
A: This is a contentious subject within the tyre industry but part worn tyres are still available. These are obviously second-hand, usually imported from the continent, so buyer beware. The Motor Vehicles Tyres (safety) Regulations 1994 gives the buyer some safety protection as it is a legal requirement that a part-worn tyre must be inspected inside and out for defects and be marked as “part worn” on the sidewall before being sold.¬†

Q: Can I buy remould tyres?
A: Remoulded tyres are second-hand and the debate regarding their safety rages on. Up to January 2004, there was no legal standard for remoulded tyres to adhere to but, since then, they have to conform to ECE Regulations 108 and 109 and carry an “e” mark, so ensure this is on any remoulded tyre you purchase.

Q: My new car has run flat tyres. What should I do if I have a puncture?
A: Run flat tyres work by supporting the vehicle for a short period of time when deflated for limited speeds and mileages. If alerted by your dashboard’s tyre-pressure monitor, have the tyre inspected as soon as possible and always replace with another run-flat tyre.

Q: Is it good practice to swap my front and rear tyres every couple of months to ensure they will all have the same amount of wear when the time comes to replace them?
A: Yes, but a couple of months is perhaps too frequent, 10,000 miles is probably a better interval. Front tyres usually wear out more frequently than the rears so swapping them will even the wear. It is advisable to keep the tyres on the same side of the car, as some types are designed to rotate in one direction only, as indicated by an arrow on the sidewall.

Q: If I have a crash and my tyres are found to be defective, will that invalidate my insurance?
A: It is likely, although tyres tend only to be inspected at an accident scene when the incident is serious. Nonetheless, this is no excuse as you have a legal responsibility to ensure your car is in roadworthy condition. Furthermore, you could receive a £2,500 fine and 3 penalty points per defective tyre.

Q: Can I be done for defective tyres if I’m driving to a tyre shop to have them changed?
A: You should never drive a car on a public road fitted with a defective tyre as not only could your insurance be invalid, you are putting yourself and other road users at risk. If you are stopped by the police, and you prove you are driving the car to a pre-booked appointment to have the work done, you could still be charged. Regular inspections of your tyres should prevent this situation from happening. Should you be in doubt, fit the spare tyre.

Q: What does the coding and numbering found on the side of tyres mean?
A: The letters and numbers on the sidewall of a tyre look complicated. However, they explain the exact specification of the tyre you have.
For example:
205/50 R15 91V E4
205 – width of the tyre in millimetres
50 – known as the aspect ratio, this is the height of the tyre sidewall as a percentage of the width. In this case 50% of 205mm
R – radial construction
15 – diameter of the tyre’s inner rim in inches
91 – this is the load capacity of the tyre. The number is part of an index of corresponding weights, in this case 615kg
V – all tyres are given a speed rating. This indicates the maximum speed for this tyre at full load. In this case it is 149.1mph. Speed ratings range from S (max 111.8mph) to ZR (150mph+)
E4 – this is the ECE type approval mark, which demonstrates the tyre has been tested as high quality by the European Regulatory Authorities.

For more information visit Tyresafe 

The information on this Site is provided on the understanding that GEM Motoring Assist is not rendering legal or other advice. You should consult your own professional advisers as to legal or other advice relevant to any action you wish to take in connection with this website.

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