New EU data reveals a significant discrepancy between official and real-world CO2 emissions for plug-in hybrid electric vehicles (PHEVs). For cars registered in 2024, real-world emissions averaged 145g of CO2 per km, while official tests showed only 24g per km. This represents a six-fold increase over laboratory results.
The gap has widened over the last year. In 2023, real-world emissions were 138g per km compared to 28g per km in official tests, which was five times higher. While official emissions figures dropped by 15% between 2023 and 2024, actual emissions increased by 5% during the same period.
PHEVs currently make up 9.8% of EU car sales. Real-world data, collected from fuel monitors on 220,000 vehicles, shows that PHEVs emit only 14% less than conventional combustion engine cars, which average 169g per km. This is a decrease from a 17% difference observed the previous year.
The European Union is planning regulatory updates in 2025 and 2027 to tighten the gap between official and real-world emissions. However, the industry group ACEA is pushing to cancel the 2027 update. The EU Council is expected to debate the issue on October 12, and a vote in the EU Parliament is scheduled for November.
