Tyre Basics and Facts


Like anything you need to pay for quality to get quality! It is worth investing in better tyres as the benefits; make the extra cost outlay worthwhile. These include lower fuel consumption, lower road noise, better handling, better grip, longer tyre life and shorter stopping distances.

EU legislation introduced in 2012 means that all tyres being sold by retailers now display a label, detailing various performance attributes. The tyres are given a rating system (similar to that of white goods) with grades awarded based on how safe the tyres are, braking distances in the wet, fuel-efficiency and noise levels. The decision on which tyre to choose has become an awful lot easier.

Tyre Tread / Pattern

The tread pattern works to remove water on the road surface, enabling the tyre to grip steer and accelerate properly. If this is worn too low it will not be effective (see tread depth).

Asymmetric or directional tread patterns are designed to be more effective in one direction only, so fitting a tyre the wrong way round can dramatically affect its performance. Asymmetric tyres have a marking on the tyre sidewall to indicate which side of the tyre should be fitted to the outside of the car whereas manufacturers place a rotational indicator on the side of directional tyres to show which way round it should be fitted.

Tyre Tread Depth

The UK law requires car tyres to have a minimum of 1.6mm of tread across the central three-quarters of the tyre, around its entire circumference. However, some tyre safety experts advise that for optimum safety performance, that consideration should be given to replacing tyres when tread depth falls below 3mm. Increasingly this 3mm limit is being voluntarily adopted by company and fleet  users, police etc. In the interest of safety is it not worth it?

Remember – by having your wheel alignment regularly checked you can extend the life of your tyres.

Tyres Pressures

Like alignment settings, motor manufacturers also specify recommended tyre pressures for every vehicle. These can usually be found in your vehicle manufacturers’ handbook, inside the fuel filler cap or on the driver’s door sill. The pressures vary from model to model and can also vary from front wheels to back wheels or according to loading – normal or fully loaded. So it is important to look them up and set them to the correct tyre pressure psi (pounds per square inch) or bar.

The pressure should be checked at least once a month and ahead of a long journey. Incorrect inflation also contributes to excessive tyre wear, heavy fuel consumption and could cause tyre overheating and the potential danger of sudden air loss (blow out) at speed.

When Tyres Should Be Changed

  1. Tread depth wears down to either; legal limit of 1.6mm or personally adopted limit 3mm.
  2. Damage to tyre – e.g. Bulges in tyre wall, deep cut or chunks missing, severe punctures etc.
  3. Old – Tyre starts degrading due to old age – perishing, cracking etc.
  4. The tyre on the same axle has become damaged and needs replacing.

Tyre Balancing

When tyres are fitted they should be balanced, to limit the vibration. In general a standard balance should be sufficient but if vibration persists and/or there is some pull (after a full four wheel alignment) then a specialised Road Force Balance may be necessary.


Tyre pressure monitoring systems (TPMS) have become increasingly popular, including aftermarket systems and in line with EU legislation, all new cars built from 2012 onwards must include a TPMS. The systems monitor loss of pressure inside the tyre and alert the driver to this problem. Not only will this help drivers improve their fuel efficiency (as it will ensure correct inflation levels are maintained), it is also expected to reduce a number of tyre related accidents as blowouts often occur as a result of under-inflated tyres.

Drivers of vehicles with TPMS fitted should ensure their systems are regularly serviced in line with vehicle manufacturer’s specifications to ensure their ongoing reliability and accuracy.