Energy
T&E urges EU to uphold plug-in hybrid emissions rules
Transport & Environment warns that freezing plug-in hybrid accounting rules would increase fuel costs for consumers and obscure real-world emissions.
Key points
- PHEV models registered in 2024 emitted six times their official CO2 figures on the road.
- Real-world emissions for PHEVs are only 14% lower than conventional combustion and hybrid vehicles.
- Germany is pushing to freeze upcoming utility factor corrections in ongoing automotive negotiations.
What happened
Transport & Environment (T&E) has called on governments to maintain scheduled corrections to plug-in hybrid electric vehicle (PHEV) carbon dioxide accounting rules. According to a report published by CleanTechnica, the discrepancy between official test figures and real-world emissions for PHEVs is widening significantly.
The analysis of European Environment Agency data indicates that vehicles registered in 2024 emitted roughly six times their official CO2 ratings during actual road use, an increase from a fivefold divergence in 2023. This variance adds up to €680 annually in extra fuel expenses for the typical driver of a 2024 model.
Why it matters
Official test metrics suggest that PHEVs reduce emissions by 83% compared to standard vehicles. However, T&E found that actual emissions are only 14% lower than conventional combustion and hybrid cars. Data shows the internal combustion engine runs for approximately one-third of the distance driven, even while the battery is engaged.
The European Union has sought to address this through adjustments to the utility factor, which determines the proportion of electric driving factored into official emissions calculations. T&E noted that initial adjustments in 2025 and 2026 prompted manufacturers to install larger batteries and improve electric range.
Despite these improvements, Germany is currently advocating to halt upcoming utility factor adjustments as part of broader automotive package negotiations with France. T&E warns that freezing the regulations at current levels would leave real-world emissions underestimated by 56%.
What comes next
The next phase of accounting rule revisions is scheduled to begin in November 2026. T&E has urged the European Parliament and Council to resist efforts to roll back the measures, arguing that maintaining the standards protects consumer finances and prevents the overstatement of electric driving ranges by manufacturers.
Original reporting
This article draws on the following reports. Read them in full on the publishers’ sites.
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Written by the CEII Desk, the Centre’s automated newsroom, from the reporting credited above and CEII’s own data. Facts are attributed to their sources; the publishers have not reviewed this article. Spotted an error? Tell our editors.
