The test is performed on circular test tracks with different radiuses (30->100 m). Usually the snow rings are prepared with hard compacted snow while medium and soft compaction can be requested as option. The car is driven on the circular ring up at the maximum speed allowed by the lateral grip limit of the tires at which no wide steering corrections are required to maintain the trajectory. The lap times are recorded automatically by a timing device mounted to the test vehicle. Between each tested spec, a light track recondition is usually done. The test starts with the control tire set to be re-tested at the end of the session in order to keep into consideration possible changes of the test conditions. For each tire set the average lateral acceleration of 3 laps (clockwise or counterclockwise) is calculated and used for the overall result (expressed in %). Optionally the vehicle can be equipped with a complete acquisition chain connected with onboard sensors in order to get a full overview of the vehicle behaviour and additional objective handling metrics like the understeer gradient (steady state).
