Asymmetrical tyres are those which have a tread pattern that is different from one side to another – ie non-symmetrical. Tread patterns vary, with some giving particularly good dry grip and others having characteristics designed to enhance wet performance. An asymmetrical tyre offers the best of both worlds by combining the two patterns across the width of the tread.
The outside of the tread pattern consists usually of larger stiffer tread blocks that help with cornering performance whilst the inner blocks are particularly suited to wet performance. Very often, asymmetric tyres feature a continuous central rib in the pattern that aids straight-line stability. Asymmetric tyres must be fitted with the correct side facing outwards – this is marked on the sidewall of the tyre – to get the best performance. Some asymmetric tyres are also directional and in these cases the vehicle will have specific “left” and “right” handed tyres. Tyres such as this are usually only found on ultra high performance vehicles.
Below is a small selection of typical asymmetric tread patterns available from major tyre manufacturers:
You can clearly see the difference between the tread patterns of the inner and outer shoulder