In order to take into account the difference in the level of CO₂ emissions determined under the New European Test Cycle (NEDC) and those determined under the new Worldwide Harmonised Light Vehicle Test Procedure (WLTP), a methodology for correlating the CO₂ emission values has been put in place through Commission Implementing Regulation (EU) 2017/11532 with regard to passenger cars.

The correlation methodology is to deliver results that ensure that the reduction requirements set out in Regulation (EC) No 443/2009 are of comparable stringency under the old and the new test procedures. Approval authorities and technical services should therefore, together with manufacturers, strive to ensure that WLTP and NEDC tests that are carried out for the purpose of this Regulation are performed under test conditions that are comparable and coherent with the objective of this Regulation.

For that purpose, it is necessary to clarify certain aspects of the WLTP test conditions that should apply for the correlations performed in view of providing WLTP and NEDC monitoring CO₂ emissions data for vehicles newly registered in 2020. Those clarifications should apply without prejudice to the procedure and requirements set out in Commission Regulation (EU) 2017/11513 and without affecting the validity of any type approvals granted on that basis.

It is also necessary to determine the difference in 2020 between CO₂ emission values declared by the manufacturers for the purpose of the emissions type approval and those measured pursuant to Regulation (EU) 2017/1151. Manufacturers should therefore be required to calculate and report to the Commission the WLTP CO₂ emission values for all new passenger cars registered in the calendar year 2020 using the measurement values for vehicle H and L as input to the interpolation method.

For a limited number of interpolation families, only vehicle H measurement values will be available in 2020. The number of those families should be closely monitored and the Commission should consider excluding those families from the calculation of the 2020 reference data, should there be a significant increase in the number of such families as compared to the 2018 situation.

The transparency in the emissions testing should be improved, and data on the WLTP tests as well as on the correlation results should therefore be made available to the Commission. This will allow the Commission to swiftly identify and address issues and possible inconsistencies relating to the implementation of the procedures. For that reason, the input data matrix should be completed for each WLTP test performed and be transmitted to the Commission in its entirety as part of the correlation tool data exchange. To ensure confidentiality, the input data file should be encrypted in view of the transmission.

The measures provided for in this Regulation are in accordance with the opinion of the Climate Change Committee,