Tyres are the only point of contact between your car and the road, yet they are one of the most overlooked essentials of motoring - and potentially a big expense.
Your choice of tyres and how you maintain them can affect safety and fuel economy, but they tend to be what’s known as a “distress purchase” - an item that’s bought at a critical time, such as after a puncture or an MOT failure.
Depending on the type of car you drive, tyres themselves can cost anything from around £50 each for a budget brand like Nexen, Riken or Ovation, to hundreds of pounds from premium names such as Continental, Michelin and Pirelli.
A recent survey* found that one in 10 drivers have never checked their tyre pressure or tyre tread, while almost half are unaware of what the legal limit is for tyre tread on a passenger car.
Freedom of Information data obtained by savings site Confused.com** revealed that one in four (23%) of MOTs are failed by defective tyres, with ‘bald’ tyres being the most common tyre-related reason for rejection.
And with motorists facing three points on their licence and up to £2,500 in fines per tyre, penalties for tyre offences can cost drivers dearly.
For the record, the legal limit for minimum depth of the tread on your tyres is 1.6 millimetres across the central 75% of the tread, around the complete circumference of the tyre.
However, for safety reasons it is recommended that you replace your tyres before the legal limit is reached. At 1.6mm in wet weather it takes an extra two car lengths (eight metres) to stop at 50mph compared to tyres with tread of 3.0mm.
Repair or replace?
If you suffer a puncture or a blowout (a catastrophic tyre failure) and the tyre has to be replaced immediately, often at the roadside, you have various options.
If your car has a spare tyre or “space-saver” (a skinny temporary tyre which has a short life span and a speed restriction), you will have to use it to replace the damaged tyre.
Tyre repair kit
If you don’t have a spare tyre, as is increasingly becoming the case, you will have to use the tyre repair kit supplied instead. This is basically a can of foam which you squirt into the tyre via the normal tyre vale, and then inflate using the compressor also supplied. However, tyre foam is not effective on all punctures, so then there’s no option but to call for roadside assistance.
It’s also worth remembering that your foam-inflated tyre will need replacing within a couple of hundred miles on average, which could be as little as a few days for some. You will also have to buy a new tyre repair kit.
Sometimes you might suffer a slow puncture (where a tyre gradually loses pressure over a period of time). Here, your first port of call should be a garage or tyre fitter (many are mobile too).
They should check for free and then give you an option, but ask first. A slow puncture could be caused by an object embedded in the tread, such as a nail, damage caused by potholes, a defective valve or even a faulty seal with the wheel.
There are strict safety regulations concerning the repairs of tyres. For instance, only repairs to the central 75% of the tyre (the main tread area) are allowed, and nothing near or on the sidewall.
Also, if the diameter of the damaged area is larger than 6mm, a repair should not be attempted. This means it may be possible to repair a tyre that has been pierced by a nail or a screw, but not a larger object. Splits, cuts and gouges should not be repaired either.
If your tubeless tyre is repairable, the tyre fitter might fit a plug. It is inserted through the puncture hole and vulcanises together with the tyre rubber, creating a seal. Alternatively, inner tubes can be fitted to tubeless tyres.
Repairs will save you money – anything from £15-25 compared to a new tyre – but in terms of safety, there is no substitute for investing in a new tyre.
Some cars are fitted with run flat tyres which are designed to keep working for a short while even after they suffer a puncture. So if you get a puncture on a cold, dark night, there's no need for an uncomfortable roadside tyre change – you should be able to safely drive home if it’s close enough.
However, most tyre retailers will not repair a run flat tyre following a puncture because if it has been driven its strength may have been compromised.
Some slow punctures are caused by faulty valves or issues with the seal between the wheel and tyre.
When you get a new tyre fitted there is a sealant placed across the rim of the tyre to help prevent any air escaping. Sometimes this has been incorrectly applied or, over time, the seal just wears away. In this case it just needs a new application of sealant by a tyre fitter.
If you have a leaking alloy, it can be fixed by removing all the corrosion or oxidisation and then repainting the inside of the wheel. Faulty valves can also be fixed cheaply.
Other ways to save money include buying used or part-worn tyres. This option is frowned upon for safety issues, but many argue that if you buy from a reputable dealer, it’s no different than driving on tyres that come with a second-hand car.
If you have looked into buying a part worn tyre and believe that the tyres on offer were not safe, you should contact your local Trading Standards.
Remould or retreads are another low-cost option, sometimes costing as little as half the amount of a budget tyre, and are widely used on lorries. These re-use the carcass of a worn out tyre and reclad it with fresh tread to giving it a new life.
While retreads are manufactured and tested according to strict safety standards, doubts still hang over them because they are ultimately not new and anything used has a greater potential to fail.
For more information about tyres and safety, go to TyreSafe*** - a UK charity dedicated to raising awareness of the importance of correct tyre maintenance and the dangers of defective and illegal tyres.
***TyreSafe - http://www.tyresafe.org/