Know Your tyre types

With most modern cars, the standard tyres have a symmetrical pattern running the entire tread, whilst some high performance cars have special tread patterns in their tyres. It is important to ensure these tyres are fitted the right way round on the wheel, as failure to do so will result in MOT failure.  

ASYMMETRIC TYRES

Tyres with differing tread patterns on the inner and outer edges of the tread are known as asymmetric tyres and they are designed this way to improve the overall performance of a car.

Large stiff tread blocks on the outside edge of the car help with cornering  and smaller tread blocks on the inside edge are designed to shift water and further improve wet grip. The middle of the tread often features a continuous rib to help straight line stability.

The tyre sidewalls should be labelled 'inside' and 'outside' to ensure the tyre is fitted correctly.

DIRECTIONAL TYRES

These tyres are designed to rotate in only one direction. Directional tyres are good for dispersing water that can build up in front of tyres. This type of tyres also reduce road noise and improve directional stability.

To help with fitting these tyres, there is usually an arrow on the tyre sidewall to indicate which way it will rotate.  

WINTER TYRES

The rubber on standard tyres begins to harden at temperatures under 7°C, which leads to reduced grip on wet, cold, icy and snow covered roads. Winter tyres are designed to stay soft and pliable in cold temperatures and will give up to 60% better grip in the road.

Winter tyres can also improve braking, handling & traction in all winter driving conditions thanks to many special grooves, known as sipes, in the tread. Across Europe it is a legal requirement to keep a set of summer and winter tyres. Use of the tyres in this country is dependent on the driving conditions in your local area.

Winter tyres are not suitable for use throughout the year as Summer tyres are better equipped for higher temperatures and drier roads. Winter tyres must be fitted in a set of four, otherwise the stability and balance of a car will be adversely affected.

ALL SEASON TYRES

As an alternative option to Winter tyres, vehicle owners can opt for All Season Tyres. These tyres are created with a high silica contact for low temperature flexibility and a tread pattern that sits between those of a normal summer tyre and winter tyre. 

This type of tyre rarely performs better than a specialist tyre, but are better than summer tyres in winter conditions and are less hassle and less cost than the alternative of switching over tyres twice a year.

PART WORN TYRES

The safest option when getting replacement tyres is to have new ones, but part worn tyres can be used so long as various criteria are met. The minimum safety standards are set for the supply of part worn tyres by the Motor Vehicles Tyres (Safety) Regulations 1994.

These regulations state that part worn tyres should have an EC approval mark and a speed and load capacity index moulded into the sidewall at the time of manufacture. Also, all part worn tyres must be marked with the words 'PART WORN' at least 4mm high.

It is illegal to be in possession of unsafe tyres with the intent to sell.

TEMPORARY

Most modern cars are sold by vehicle manufacturers with a non-standard spare wheel and tyre that is slimmer and lighter to save weight and space in the car. Because of this, these temporary tyres are limited to 50mph when in use. 

Known as a space-saver wheel, it is intended for emergency use in a temporary capacity. Drivers are advised to replace or repair the original tyre as soon as they are able.