WET TESTING

THE conditions where most drivers will get close to or overstep the limit are in the wet, so these tests are key to any tyre’s performance. It’s no surprise that it’s part of the EU labelling system, but instead of looking at just braking we also test handling, lateral grip and how the tyre resists aquaplaning in deep water.

The handling was done at the 1.1-mile track that snakes across the Texan scrub. It mimics the circuit at Continental’s German centre right down to tons of tarmac imported in a series of containers to replicate the surface.

The result is based on an average of several lap times. Before heading to the track, we completed up to 10 laps of the 55-metre wet circle, which measures pure lateral grip. Again, the result is based on an average of lap times. Both tests and dry handling were done in a previous-generation Volkswagen Tiguan – a model that had our test tyre as original equipment.

Braking was done using the rail system, which ensures that precisely the same piece of track is used each time to assist getting consistent results. We did a series of stops and measured the distance taken to halt from 50mph. The result was based on multiple stops with outliers removed.

The water depth on all these tests was around a millimetre, but to see how the tyre coped with deeper flooding, we measured both lateral and longitudinal aquaplaning. The curved test was done in 6mm-deep water and the straight in 8mm. For the former the car was driven at set speed increases through a soaked section of a tarmac circle. The loss of lateral grip was measured as the speed went up, and the tyres compared using industry standards.

For the straight test, the rail was used and the car was accelerated with one wheel in water. The difference between the two was measured, with the speed when the slip exceeds 15 per cent recorded – the point at which control is lost. An average of multiple runs was used to get the final comparison.