How to drive in heavy rain

Wet grip

It's all about safety

Some tyres have better wet grip than others. Tyres with excellent wet grip will have shorter braking distances on slippery roads, helping to keep you safe in the rain.

The Wet Grip grading is all about how well the tyre performs in wet conditions. The rating of your tyre makes a big difference to your ability to stop quickly in tricky conditions. If you brake from 50mph on a wet road, then a vehicle with 'A' rated tyres will stop 18m sooner than a vehicle with 'G' rated tyres. If you have to stop suddenly on the road, the wet grip rating of your tyre is critical in determining whether you stop in time or not.

Did you know?

The difference in stopping distance between an 'a' and 'g' rated tyre is the same length as eight smart cars.

Each grade represents a 3m (length of 1 car) or 6m (length of 2 cars) shorter braking distance. That’s something to think about seriously when you or your loved ones are in the car – it’s all about safety.

How do tyre manufacturers measure the grading?

According to the new tyre label legislation, wet grip can be tested in one of two ways.

The first is the wet braking vehicle test, which measures wet braking performance on a wet road surface, braking from 80km/h to 20km/h.

The second test is a skid trailer test, which measures friction between the road and a tyre, conducted at 65km/h. The end result of both tests provides a Wet Grip Index (WGI), which describes the improvement in percentage in relation to the reference tyre.

Tyre manufacturers are required to comply with the legislation, which means that you have reliable, objective and comparable data to help you chose the right tyre for you. The testing is:

  • Self Certified
  • Using EU-approved methods
  • Enforced by local National Enforcement Authorities