Mercedes-Benz: WLTP consumption and emission values.
Since 1 September 2017, some new vehicles have undergone type approval in accordance with the Worldwide Harmonized Light Vehicles Test Procedure (WLTP). This puts the vehicles through a more realistic test procedure for the measurement of fuel consumption and CO₂ emissions. Since 1 September 2018, the WLTP has replaced the New European Driving Cycle (NEDC) on a step-by-step basis.
https://www.mercedes-benz.com/en/vehicles/wltp/wltp-fuel-consumption-and-emission-values/