This testing philosophy allows higher scoring vehicles to prove the robustness of their performance under more difficult conditions and benefits models with a good and balanced overall-performance.
This means that vehicles with index scorings above certain thresholds are given the chance to confirm the outstanding performance demonstrated in the standard tests by entering the additional robustness test stage. Cars lacking robustness in the second stage testing might lose a part of their score, but their rating will not fall below three stars.
In order to qualify for additional robustness testing, the average score of the three indices (Clean Air, Energy Efficiency and Greenhouse Gas) shall be not less than 5/10 and the minimum of the three indices shall not fall below 3.5/10.