Dunlop DriversKnow

Asymmetric tyres

An asymmetric tyre has different tread patterns on its inner and outer sides, giving it a distinct performance advantage over a tyre with a symmetrical or directional tread.

• The tread pattern on the inner side of a typical asymmetric tyre has more grooves giving better grip on wet roads
• The outer side has a higher plain surface area, the benefit of which becomes apparent when cornering at speed on a dry road

Unlike a directional tyre, an asymmetric tyre can be used in any position on the vehicle. It is very important however, to follow such wording as 'inside' and 'outside' on the tyre's sidewalls to ensure that the tyre is fitted 'the right way round'. As with directional tyres, incorrect fitment can seriously impair performance. And, again if you do use a wheel with an incorrectly fitted asymmetric tyre, it should be regarded strictly as a 'Temporary spare'. Please note:

• A 'Temporary spare' is limited to 50 mph (80 kph)
• A car whose tyres are not fitted in accordance with the instructions on the sidewall will fail its MOT
• Some tyres are both asymmetrical and directional. These tyres carry markings on the sidewall which a) indicate the correct direction of rotation and b) identify the inner- and outward-facing sides. Failure to observe these instructions will impair tyre performance. The above recommendations will also apply.

(Reproduced by kind permission of the BRMA)

Directional Tyres

Designing a tyre tread which will operate equally well rotating in either direction inevitably involves compromises which limit ultimate performance in some respects.

Directional tyres, on the other hand, are designed to rotate in one direction only (indicated by a conspicuous arrow pointing in the direction of rotation on the sidewall along with the word "rotation"); so performance - wet grip, directional stability and handling - far from being compromised, is optimised.

Obviously, a directional tyre can deliver this improved performance only if it is correctly fitted to ensure that it rotates in the direction indicated on the sidewall.

What happens if you are unfortunate enough to have a puncture and your spare wheel is fitted with a directional tyre designed to rotate in the opposite direction to the tyre which it replaces? You are recommended to treat the spare wheel as a 'Temporary spare', drive at reduced speed and have the tyre correctly refitted as soon as possible.

(Reproduced by kind permission of the BRMA)

Maximum Flange Shield

The Dunlop MFS (maximum flange shield) system protects expensive alloy wheels from kerbing.

A profile of rubber runs around the circumference of the tyre, located low on the side wall above the wheel flange creating a buffer zone.