Why regular condition checks are important
Tyres play a vital role in road safety as they are the only point of contact a car has with the road. Basic checks, such as inspecting the pressure and tread levels plus the tyre’s overall condition, can make a crucial difference in how a car performs.
And while safety is paramount, properly maintained tyres can also reduce fuel bills and have a longer life, thus cutting costs.
Tyre safety is the responsibility of everyone, whether it is the individual company car driver or the business they work for.
Why is checking tyre tread depth important?
The legal minimum tread depth for cars in the UK is 1.6mm throughout a continuous band comprising the central three-quarters of breadth of the tread and around its entire outer circumference.
As a general rule, tyre treads are designed to give good grip on all types of road. But, on wet roads especially, the grip decreases as a tyre’s tread pattern wears down or as the depth of water on the road increases.
In wet weather, tyre tread grooves help to remove water from the contact area between the tyres and the road surface, meaning the driver can brake, steer and accelerate properly.
Without adequate tread depth, tyres may not be able to perform properly in wet conditions, reducing driver safety on the road. It is therefore advisable to consider replacing tyres well before they reach the legal minimum.
Drivers whose tyres fail to comply with the minimum tread depth requirements risk a fine of up to £2,500 and three penalty points for each illegal tyre.
The 20p test
A quick and easy way to see if your tyre tread exceeds the minimum legal tread depth is to take the 20p test, one recommended by tyre safety organisation, TyreSafe.
Simply place a 20p coin into the main tread grooves of the tyre. If the outer band of the 20p coin is obscured when it is inserted, then the tread is above the legal limit.
If the outer band of the coin is visible, then the tyres may be illegal and unsafe and should be checked immediately at a garage or by a qualified tyre professional.
Try and check at least three areas around each tyre. As the test is so quick and easy, tyres should ideally be checked once a month in this way.
What type of tyres?
With changeable wintery weather and fluctuating temperatures across the country, the first and most important element to ensure tyre safety is to carry out regular checks.
While various tyre types are available, all will need to be in good condition and at the right pressure to perform at their best throughout the colder months ahead.
Summer tyres are most commonly fitted across the country and designed for the road conditions experienced generally in the normal UK climate.
All-season tyres are gaining in popularity, however, as a result of new developments in technology, as they provide an all-year alternative for use in climates that suffer less severe winter conditions. They are manufactured with a slightly different rubber compound designed to combine the benefits of summer and winter tyres.
Tyres like the Michelin ‘CrossClimate’, for example, offer the advantages of summer tyres in wet braking, dry braking, longevity, and fuel efficiency, and the advantages of winter tyres in traction and braking for driving in cold or occasional snowy conditions.
Pure winter tyres, on the other hand, are manufactured with a rubber compound and tread pattern specifically designed to perform when temperatures drop to 7°C and below. They are useful in snowy and icy conditions, such as are found in the highlands of Scotland, for example, as they have higher levels of grip in these conditions.
Winter is particularly challenging for all types of tyres and regardless of which is fitted, the distance a vehicle takes to stop may well increase while grip around corners is also likely to be reduced.
This factor especially applies to commuters and business motorists who are on the roads in the coldest conditions in the early morning and evening.
Essential tyre checks
Drivers should check their tyres at least once a month, and before any long journeys, for pressure and condition.
While checking the tread, have a look at the tyre’s general condition. Any sign of bulges, cuts, nails or cracking need to be examined by a tyre professional.
If you’ve hit a kerb, always inspect the wheel to ensure it is not cracked – alloys are particularly prone to this – and inspect the sidewall for damage. At any sign of deterioration, the tyre should be professionally inspected as soon as possible and, if necessary, the wheel and tyre changed.
To check tyre pressure, an accurate gauge should be used to confirm that the vehicle’s tyres are at the manufacturer’s recommended pressure. Pressure should always be checked when tyres are cold, due to the expansion of air when hot which can give false readings.
Two units of measure are typically used: pounds per square inch (psi) and ‘Bar’ pressure and, as a rough guide, one Bar is equivalent to approximately 14.5 psi.
On most cars, the right pressures are located either on the door sill or behind the filler cap. Alternatively you can refer to the owner’s manual. Remember that when a vehicle is fully loaded, the pressures will typically need to be increased.
If supplied with one, always check the spare tyre for both tread depth and pressure.
Under-inflated tyres will have uneven contact with the road and will exhibit excessive wear on the inside and outside edges of the tread if they are left under-inflated for some time. Not only does low tyre pressure wear tyres out more quickly, but it provides increased rolling resistance which means reduced fuel efficiency and increased CO2 emissions.
Putting too much air in tyres can be just as damaging and costly. Over-inflated tyres will have a smaller contact area, which can lead to a loss of traction and poorer braking distances. Over-inflated tyres will also wear heavily and unevenly across the central part of the tyre leading to a shorter lifespan than if the tyre was correctly inflated.