Facing EU city bans, are diesel’s passenger car days numbered?

Euro 6d-temp, and eventually Euro 6d, represents the latest challenge in emissions regulations for automakers operating in Europe. To comply with these, new registrations will need to satisfy requirements in Real Driving Emissions (RDE) tests that will be introduced alongside the new Worldwide Harmonised Light Duty Test Procedure (WLTP). 6d-temp will take effect for all new registrations from 1 September 2019, requiring an nitrogen oxides (NOx) conformity factor of 2.1, meaning NOx emissions cannot exceed more than 2.1 times that required in the lab, which is under 80mg/km. 6d, which will apply to all new registrations from January 2020 onwards, requires a conformity factor of 1, but with an error margin of 0.5.