Why are tyres important?
When a tyre is under-inflated, heat builds up inside the tyre, which may eventually lead to a sudden tyre deflation. Tyre failure may cause the driver to lose control of the vehicle, which is particularly dangerous on motorway carriageways.
In the event of a tyre failure, super-single tyres can present the driver with a particular challenge in terms of maintaining control of the vehicle.
Other motorists can be put at risk by any tyre debris left on motorway carriageways/roads.
Fitting a replacement tyre on a motorway hard shoulder is a highly dangerous activity.
Correct tyre maintenance can greatly reduce these risks and provide a safer working environment for drivers and fitters.
2. Vehicle handling
The tyre is a complex component of a vehicle that has been engineered to work in harmony with the vehicles sophisticated brake, steering and suspension systems. When a tyre is under-inflated, the tyre contains insufficient air to support the weight of the vehicle properly, which adversely affects acceleration, braking and cornering.
3. Fuel economy
By keeping tyres at their correct pressure, drivers can travel further on each tank of fuel and help to reduce CO2 emissions.
When tyres are under-inflated, the contact patch with the road surface increases, causing increased drag, which in turn places more load on the engine
The rolling resistance of an under-inflated tyre increases as it requires more energy to return to its original shape after each contact with the road
Keeping tyres correctly inflated helps commercial fleets to minimise their cost per kilometre rate, while economising on fuel costs.
4. Premature tyre wear
Keeping tyres inflated to the recommended tyre pressure level for the vehicle ensures even tyre pressure distribution, optimum handling, and consequently a more even wear rate, keeping the tyres in service for longer.
- Driving on under-inflated tyres places excess stress on the tyre shoulders, causing uneven wear towards the outside edge of the tread
- Under-inflated tyres also heat up more quickly than correctly inflated tyres, and in extreme cases can lead to tyre failure
- Over-inflation causes high wear in the centre of the tread.
Current tread depth legislation requires that truck tyres must have a minimum of 1mm of tread in a continuous band throughout the central three-quarters of the tread width and over the whole circumference of the tyre. The same regulation applies to regrooved tyres. The driver of the vehicle is responsible for making sure his/her tyres are legal and in a roadworthy condition. The penalty for driving with an illegal tyre is 2,500 and three penalty points per tyre.
When driving in wet weather, the tread pattern of the tyre helps to evacuate surface water from the road. As the tread begins to wear down, the tyre gradually loses the ability to evacuate all the water from the road surface, which increases stopping distances in the wet. The lower the tread depth, the greater the risk of aquaplaning.
Incorrect wheel alignment may cause the tyres to scrub against the road surface to a greater degree, increasing wear and rolling resistance. If any of the wheels of a 12-wheel tractor and trailer are not properly aligned, the total drag on the vehicle increases. Misalignment may also cause greater aerodynamic drag when the tractor and trailer are not tracking parallel to the direction of travel.
Any tyre regrooving should take place at around 4mm of remaining tread. After regrooving, the 1mm law still applies. It is also law that the tyre is regrooved in the pattern designated by the tyre manufacturer failure to observe this will render the tyre illegal. If any of the tyres cords are exposed during regrooving, the tyre should be disposed of. [N.B. It is important to consider that budget tyres might not be designed with enough extra rubber to regroove tyres.]
Safe Tyre Disposal
Tyre disposal companies can be hired to remove end-of-life tyres and transport them away for shredding. The Tyre Industry Federation Responsible Recycler Scheme offers one such service to fleet companies. It operates under licence by the Tyre Recovery Association and collector members of the scheme can be located by postcode on the website www.tyrerecover.org. After reprocessing, tyre derived products can then be used for various purposes, such as landfill drainage, coastal defence, road surfacing products and childrens playgrounds.