How to buy car tyres
Which car tyres should I buy?
By Daljinder Nagra
Article 1 of 2
Tyres are critical to your car’s performance and safety. We explain when and where to buy them, and the different options available.
Tyres are a generally underestimated part of a car’s anatomy. They’re an often neglected aspect of vehicle maintenance, and replaced only when strictly necessary. However, given that every accelerative, braking and directional force applied is passing through the small area of rubber in contact with the road, it’s essential to make sure they are in good condition and that you buy wisely.
Changing tyres shouldn’t just be a consideration when the tread depth is approaching the legal minimum of 1.6mm (across three quarters of the tread) – if your tyres have any lumps or bulges this suggests its structure is failing and is not fit for purpose in the eyes of the law. Similarly, if any of the tyre’s internal metal cords are exposed, it’s time to change them immediately.
Ideally, you should replace all your car tyres at the same time, but this is rarely practical because front and rear tyres wear at different rates. A tyre’s ability to grip, especially in wet conditions, will deteriorate well before this, so start looking for replacements when the depth reaches 2-3mm. A new tyre has a tread depth of about 8mm, though specialist performance tyres can come with much less than this.
But which new tyres should you be buying? Your car’s handbook will be able to guide you as to the correct size, but there are a number of things to consider.
Summer or winter tyres?
In the UK, vehicles are fitted with summer tyres as standard. These offer their highest grip levels in warm, dry conditions, but are also designed to operate safely in the wet. For most drivers they will be the default choice, given their all-round performance.
However, if you’re changing tyres during the winter, you may wish to consider specialised winter tyres. These are constructed from a different rubber compound that stays supple at lower temperatures. Below 7degC, winter tyres will generally out-perform summer tyres in terms of outright grip.
Winter tyres also features tread blocks with small cuts or ‘sipes’. These sipes improve traction on both snow and ice enormously, and will give greater control in the slipperiest of conditions.
Of course, when the temperature rises above 7degC, it’s worth changing back to summer tyres, as not only will they perform better, but winter tyres wear out a lot quicker when used at higher temperatures.
Winter tyres are identifiable by the 'snow flake and mountain' symbol. Read our winter tyre guide for further advice.
Bridging the gap between summer and winter tyres are all-season alternatives, which purport to offer improved performance in cold and slippery conditions without impinging on performance during the summer. However, their performance levels will not be as high in extreme weather conditions as dedicated summer and winter tyres.
For example, where winter tyres are a legal requirement during colder months (Germany, for instance), the majority of all-season tyres do not meet performance requirements and are unsuitable.
Run-flat tyres are increasingly popular. If you have a puncture on your journey, a run-flat tyre uses a stiffened sidewall that supports the vehicle weight, so you can travel for another 50 miles or so at a maximum speed of around 50mph.
There are many markings that could indicate your tyre is a run-flat tyre, including DSST, RFT, ROF and RunFL.
Run-flat tyres and traditional car tyres should not be mixed on the same car, as it could affect the handling.
TyreSafe, an organisation that promotes tyre safety, advises run-flat tyres should not be used on cars without a tyre-pressure monitoring system, which is used to alert you of a deflation or puncture.
It also warns against using deflated run-flat tyres when towing, as they're only designed to support the weight of the vehicle itself.
Used and part-worn tyres
It might be tempting to save money by buying used or part-worn tyres, but we don't think it's worth the risk.
It is legal for garages in the UK to sell part-worn – or second-hand – car tyres, but only if they are safe and properly marked. In addition to be being free of the defects (for example, cuts and bulges) that would render a tyre unfit for purpose, they have to:
- show all the original markings for their type and design, including speed ratings and load indexes
- feature the words ‘part worn’ in capital letters at least four millimetres high (this must be permanent, legible and not be made by cutting or branding)
- be inspected internally if they are to be sold on the rim.
Some outlets sell part-worn tyres that do not meet these standards, which means they might have suffered internal damage and could be dangerous. That's why we advise you not to buy part-worn tyres.
Car-tyre construction explained
Car tyres are a complex assembly of materials with very different properties. The following are some of the key elements:
The tread rubber compound determines how well the tyre grips on dry roads. In the wet, the best car tyres disperse water using the grooves of the tread, maintaining contact with the road and preventing aquaplaning - where the tyre rides on top of the water, rather than passing through it - which increases the likelihood of a loss of control.
2. Steel belt
Rubber-wrapped bundles of steel wire give structural rigidity to the tyre and hold the tread flat to maintain good contact with the road.
These combine with the air in the tyre to carry the car’s load. Lower, stiffer sidewalls (as found on low-profile tyres) help the tyre retain its shape better when cornering. This improves handling, but can also make the car's ride less comfortable.
The outside of the sidewall is where you will find the tyre size and specification markings, as explained below.
4. Bead wires
These are ultra-strong steel wires with extreme resistance to stretching. They hold the tyre onto the rim, even at very high speeds and when cornering.
To read about the most popular tyre manufacturers and makes visit our guide to the best car tyre brands.
Where to buy car tyres
Traditionally, tyres were usually bought from a franchised tyre-fitting chain or a local independent dealer, but there are now a multitude of different ways of getting the right rubber for your car.
One option is to buy your tyres from your vehicle’s main dealer. It’s likely it will have the right size and recommended brand for your car, which is handy if you need them quickly. Expect to pay a premium, though, as they are often supplied by specialist dealers.
Nationwide tyre fitters, such as Kwikfit, are another convenient option as they’ll quickly be able to advise you on suitable tyres for your vehicle and change them while you wait. You can often haggle, so prices can be reasonable. However, some people can find the experience quite pressured, particularly if you’re in an emergency situation.
Online sellers, such as Black Circles and MyTyres, have a very wide selection and prices can be low. But they’re not so useful if you need a tyre at short notice – you usually need to make an appointment to have the tyres fitted at a local garage.
Some online sellers will have dedicated mobile tyre-fitting services and will change your tyres for you at your workplace or home.
It’s worth contacting several different tyre retailers to compare costs. If one retailer offers you a good deal, but is further away, try asking a nearer firm to match the offer. However, you usually won't be able to negotiate with an online supplier. Ensure any quote includes the cost of new valves and balancing the tyres, as well as simply fitting them.
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