ABS (Anti Lock Braking System) - how it works and how to use it


Tyres

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The main job of a tyre is to provide a cushion between your vehicle and the road and to maintain a good, solid ‘grip' on the road surface under acceleration and whilst cornering. So it has to provide a comfortable ride, yet be as robust and hard-wearing as possible, maintaining safe and controlled manoeuvrability for your vehicle. See our page on tyre safety

To achieve this, tyres need to be carefully constructed from a combination of different ingredients. As many as 200 separate raw materials can be used in the construction of one tyre

The tread is the grooved outer layer that is in direct contact with the road. The rubber compound is designed to grip the road, resist general wear and tear, and cope with high temperatures generated by friction.

low profile tyres on a Porsch Carerra
The grooves and tread on the shoulder of the tyre are specially designed to channel water away from the surface of the tyre, maintaining maximum wet grip.

Different rubber compounds are suitable for different grip and driving conditions. For example racing cars have tyres that can work at very high temperature ranges with optimum grip, enabling prolonged usage at high speeds on the track. These tyres wear more rapidly than typical road tyres which are balanced to provide optimum steering, braking, road holding and wear capabilities.

UK law requires that your vehicle is fitted with the correct type and size of tyres for the vehicle type you are driving and for the purpose it is being used. This means fitting the right tyres, and for safety ensuring that they are inflated to the manufacturer's recommended pressure.

What about fitting low profile tyres?

Compared to conventional passenger car tyres, low profile car tyres have greater width ratio to cope with the demands of higher performance vehicles.

The key performance advantages are:

  • Improved handling and grip
  • More traction and braking power

Disadvantages are:

  • Increased road noise
  • A harsher ride
  • Less resistance to aquaplaning due to the amount of rubber on the road

The legal limit for minimum depth of the tread on your tyres is 1.6 millimetres, across the central ¾ of the tread going around the complete circumference of the tyre.

tyre wear limits
For safety reasons it is recommended that you replace your tyres before the legal limit is reached. Leading motoring organisations recommend 2mm and many vehicle manufacturers recommend replacing at 3mm.
tyre wear indicators
Most manufacturers have tyre wear indicators built into the rubber compound. These indicators can give you a good idea of when it's time to change the tyres. A regular check of your tyres can help you to avoid up to 3 penalty points and £2500 in fines (per tyre) for having tyres worn beyond the legal minimum limit fitted to your vehicle.

It is also a legal requirement to ensure that tyres of different construction types are not fitted to opposite sides of the same axle.

The two main tyre types are radial and cross-ply, and these must not be mixed on the same axle. Radial tyres have significant advantages over crossply types and now fitted to new cars almost exclusively

radial tyre construction
Mixing brands and patterns of the same construction type is permissible depending on the vehicle type and manufacturers recommendation. Check your vehicles handbook for tyre fitting details and options.

See more detail on how tyres are made, tyre safety, tyre tread patterns, and read our advice on fitting low profile tyres