80. The representative of the EC, from the Joint Research Center (JRC), introduced GRPE-94-21-Rev.1. The Chair asked if such NOx test could also work for spark ignition engines. The representative from the JRC said research work on this was still on-going, highlighting that looking at CO and lambda was potentially sufficient to derive NOx behaviour.

81. The representative of Switzerland shared some statistics about roadside inspection tests done in the country, mainly on heavy duty vehicles, highlighting the robustness of the test for roadside inspections. The representative of China confirmed the reliability of roadside inspection test to detect high NOx emitters.

82. The representative of Clean Air Association requested additional information on other after treatment technologies. The representative of the JRC noted than passive SCR was expected to be compliant with the developed test, highlighting the challenges with hybrid powertrain.