PHEV emissions in the EU are six times higher than laboratory tests suggest

A study by the research group Transport & Environment (T&E) has found that plug-in hybrid electric vehicles (PHEVs) registered in the European Union emit significantly more carbon dioxide in real-world conditions than official laboratory tests suggest. Analysis of data from the European Environment Agency reveals that the discrepancy between real-world emissions and WLTP laboratory testing has widened annually since 2021.

In 2024, the gap reached a 500 per cent discrepancy, with real-world emissions averaging 145.27 gCO2/km compared to a WLTP value of 24.2 gCO2/km. The data indicates that while official WLTP emissions averages for PHEVs decreased by 15 per cent between 2023 and 2024, actual real-world emissions increased by 5 per cent during the same period.

According to the findings, PHEVs currently emit only 14 per cent less CO2 than conventional internal combustion engine vehicles. The research suggests that despite manufacturer claims of improved performance, these vehicles are becoming dirtier in practice rather than cleaner.