NEDC 1.0: All cars registered prior to 1 September 2017 have been approved in accordance with the New European Driving Cycle (NEDC) fuel consumption and emission test, which has been in force for decades.
WLTP: All new models that have been put onto the market since 1 September 2017 and all cars registered since 1 September 2018 onwards have been tested in accordance with the new Worldwide Harmonised Light Vehicle Test Procedure (WLTP), the emission values of which are closer to reality (and therefore significantly higher).
NEDC 2.0: We are currently in a transition period. For the cars that have already been WLTP tested, manufacturers were obliged until the end of 2020 to use a European legal formula to convert the WLTP value to the old NEDC standard, called the 'NEDC 2.0' value. As of 2021, automakers may (optionally) continue to calculate a NEDC 2.0 value for WLTP cars, but are no longer required to do so.