- A tyre with 5mm or more tread is at its optimal performance level and therefore performs as originally intended.
- It is important to be aware that when driving in wet weather, the tread pattern of a tyre helps to disperse water from the contact patch with the road.
- As the tread wears down, the tyre gradually loses its ability to remove all of the water from the road surface, resulting in longer stopping distances and an increased risk of aquaplaning.
- A new tyre has at least 8mm of tread and will stop 10 metres shorter than a tyre with only 1.6mm of tread (with an average water depth of only 0.8mm)
- At or below 5mm of tyre tread, the ability of a tyre to disperse water begins to decline.
- The effect of this is to greatly increase the stopping distance for your vehicle in the wet.
- Tests have shown that the stopping distance of a tyre with a 3mm tread is approximately 10% further than a tyre with a 5mm tread.
- Tyre wear will depend on mileage, driving style and driving conditions and it is recommended that your tyres are checked every month.
- The legal limit for a tyre tread is 1.6mm across 75% of the width of the tyre around its entire circumference. Any tyre with a tread depth below this could result in the driver being fined up to £2,500 per tyre and receiving 3 penalty points per tyre.
- Although the legal minimum tread depth is 1.6mm, research carried out by RoSPA shows that tyres with this depth of tread have 25% worse performance than those at 3mm, and this would add almost 8 metres to a vehicle’s stopping distance in wet conditions.
- The deterioration in performance is apparent in other aspects of driving and vehicle control such as acceleration and cornering. A tyre with 1.6mm of tread will have 16% less cornering grip and take a further 10 metres to stop in wet conditions compared to a tyre with 8-5mm of tread.
- Motoring research organisations RoSPA and TyreSafe both recommend a change of tyres when the tread depth reaches 3mm due to the rapid deterioration in vehicle braking, acceleration and cornering below this tread depth.
*All testing carried out with a medium sized, 2.0 TDi, front wheel drive hatchback running 195/65 R15 tyres at 2.2 bar (cold). Testing was carried out on a Hot Rolled Asphalt surface with an average of 0.8mm water depth.