Finding the right tyre
Here's some of the most common tyre technical talk that you'll come across:
A tyre's sidewall markings are used to differentiate between tyre types. The size marking should be treated the same as a vehicle part number so you should always ensure that your vehicle carries the tyres exactly as indicated in your vehicle's manufacturer handbook.
Sidewall markings indicate the tyre brand, tyre name, dimensions, structure and speed capability of the tyre.
Speed rating and load index.
The speed rating indicates the maximum speed for the tyre and the load index the maximum load (weight) the tyre can carry. These are marked on the sidewall of the tyre after the tyre size indicators.
An asymmetric tyre has different tread patterns on its inner and outer sides, giving it a distincs performance advantage over a tyre with a symmetrical or directional tread. The tread pattern in the inner side of a typical asymmetric tyre has more grooves giving better grip on wet roads, whilst the outer side has a plainer surface area the benefit of which becomes apparent when cornering at speed on a dry road.
Directional tyres are designed to rotate in one direction only so performance - wet grip, directional stability and handling - is optimised.
An XL or 'extra load index' tyre has been developed specifically to hold a heavier load.
The RunOnFlat technolody allows a vehicle to keep running even when there is a sudden loss in air pressure caused by a puncture or similar damage to the tyre. Even when a RunOnFlat tyre is completely deflated it can continue to keep going for at least 50 miles at up to 50mph.
They work thanks to technology which has reinforced the sidewal of the tyre which support the weight of the car even when the air pressure inside the tyre is lost.