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Research and innovation

Closing the gap between light-duty vehicle real-world CO2 emissions and laboratory testing


978-92-79-65767-2, KI-02-17-161-EN-N
Publication date
21 February 2017
Directorate-General for Research and Innovation
Related department
Directorate-General for Research and Innovation


Responding to a request submitted by the European Commission, the high level group of scientific advisors is analysing possible ways to close the growing gap between the CO2 emissions of passenger cars certified at type approval in the laboratory and their average real-world emissions.

In its scientific opinion the high level group recommends complementing the laboratory-based world-wide harmonized light vehicles test procedure (WLTP) test cycle with a framework for the monitoring of real driving CO2 emissions. This should consist of an assessment as to whether data obtained with portable emissions measurement systems (PEMS) from the future real driving emissions testing for pollutants can be used to monitor the gap, the development of a specific real driving emissions test procedure for CO2, and the introduction of a formal reporting of the fuel consumption of passenger cars, taking advantage of on-board vehicle diagnostic systems. In order to grow the trust of the consumer in the regulatory system and the car industry, and to guarantee a level playing field for car manufacturers, the high level group also recommends enhancing coordination and enforcement at EU and Member State level, strengthening the technical oversight capacities in the EU, and ensuring transparency of the whole process.

This scientific opinion is aimed at providing an evidence-based underpinning of a policy proposal for post-2020 emission performance standards for light-duty vehicles.


21 FEBRUARY 2017
Closing the gap between light-duty vehicle real-world CO2 emissions and laboratory testing