The Green NCAP consortium is working on the development and implementation of a methodology to rate the sustainability performance of relatively new vehicles. The Horizon 2020 ‘Green Vehicle Index’ (GVI)1,2 project has been set up to accelerate and improve the Green NCAP consumer programme 3 . Within the GVI project, that started in June 2019 (and ended in January 2021), the testing and rating methodology was further developed, covering all types of available propulsion systems. In total 49 modern vehicles (Euro 6d, and Euro 6d-T) were tested and rated. TNO was one of the GVI consortium partners. Comprehensive testing programmes, both on-road and in the laboratory, give insight into emission behaviour in different potential high-emission situations. In general, the emission performance of the tested vehicles is very good, and this is a major improvement over the previous generations Euro-6 vehicles. The introduction of RDE legislation clearly shows an effect, successfully reducing a large part of the gap between type approval emissions and emissions during real-world driving. Under some circumstances though, elevated pollutant emissions may still occur. This is for example the case during a cold engine start, high driving dynamics, prolonged idling and DPF regenerations. The GVI programme provided insights in the emission levels during these circumstances. Moreover, in the measurement programme non-regulated emissions were considered as well, like NH3, N2O and particle number down to 10 nm (PN10).