What Is An Asymmetric Tyre & How To Identity Them
With a huge variety of tread patterns and sizes, tyres come in a wide variety of designs, but they can all be narrowed down to three main types: asymmetrical, symmetrical (also known as multi-directional) and directional.
You may be surprised to learn that not all tyres are equal. With a huge variety of tread patterns and sizes, tyres come in a wide variety of designs, but they can all be narrowed down to three main types: asymmetrical, symmetrical (also known as multi-directional) and directional.
Symmetrical tyres, as the name suggests, have a symmetrical tread pattern that is the same on both the outer and inner sides of the tyre. This allows the tyre to rotate in either direction, and it can be fitted at any of the four positions on the vehicle without problems. The simple tread pattern makes them cheaper than the other options, but they are also less adaptable to varying road and weather conditions. They used to be commonplace, but nowadays tend to be used for town and city driving. Since they are multi-directional, there is no right or wrong way of fitting them to the vehicle.
Asymmetrical tyres use different tread patterns on the inside and outside edges of the tyre to great effect. Large blocks on the outside edge of the tyre provide excellent traction in dry conditions, and with a large contact area they give good road handling. Smaller tread blocks on the inside edge of the tyre give superior grip in wet conditions, with an increase in the number of grooves serving to displace water efficiently on wet roads. This reduces the chances of aquaplaning, where the tyre skates on water rather than gripping the road's surface. Provided that the larger tread blocks are positioned to the outside, asymmetrical tyres offer unrivalled grip and roadholding in all weather conditions for a safe and secure drive.
Asymmetrical tyres always have the words 'inside' and 'outside' stamped on to the sidewalls to ensure that they are correctly positioned on the vehicle. Fitting asymmetrical tyres the wrong way round compromises the tyre's ability to cope with road and weather conditions correctly.
Directional tyres usually have an arrowhead pattern that is designed to rotate in one direction only for optimum performance. When correctly fitted they ensure excellent road holding, even under the wettest conditions, with superb traction. Because of the level of grip they provide, even on wintry roads, they are often used as winter tyres. In order to achieve the desired level of grip, directional tyres must always be fitted correctly, with the stamped arrowhead on the sidewall facing in the direction of travel.