G = pbfc of candidate tyre

G = average mfdd of candidate tyre

test tyre(s) means a candidate tyre, a reference tyre or a control tyre or tyre set that is used in a test run

Wet grip performance comparison between a candidate tyre and a reference tyre using a control tyre

Calculation of the wet grip index of the candidate tyre

Wet grip index (G) means the ratio between the performance of the candidate tyre and the performance of the standard reference test tyre.

The wet grip index of the candidate tyre (G(T)) is calculated as follows

where: G(T) = wet grip index of the candidate tyre as measured in one test cycle

Where the candidate tyre size is significantly different from that of the reference tyre, a direct comparison on the same instrumented passenger car may not be possible.

t is the measured wet surface temperature in degree Celsius when the candidate tyre (T) is tested