As an instrument of its climate protection policy for transportation, the European Commission has adopted Regulation (EU) 2017/2400 to implement CO2 certification for heavy-duty vehicles (EUR-Lex – 32017R2400 – EN – EUR-Lex (europa.eu)). The aim is to improve market transparency with regard to the CO2 emissions and energy efficiency of the vehicles concerned. Currently, the regulation only applies to trucks. Predefined reference trailers are used to calculate CO2 values for vehicle combinations. In the future, the EU would also like to include trailers and real bodies in the CO2 certification. The European Commission is currently working on a method to also calculate their CO2 values. The corresponding regulation and the calculation method are to be completed by the end of 2021.