Analysis of 2024 real-world data by Transport & Environment indicates that plug-in hybrid electric vehicles (PHEVs) produce emissions nearly six times higher than official WLTP test figures. This discrepancy is attributed to a market shift toward heavier, more powerful models with insufficient electric motor capacity.
A utility factor (UF) correction is scheduled for November 2026 to align official accounting with actual climate impact. Previous adjustments in 2025 demonstrated that such regulatory changes can incentivize manufacturers to improve technology and extend electric ranges to reduce CO2 emissions.
Projections suggest that increasing electric ranges to 140–220 km by 2030 could keep PHEV emissions at or below 50 gCO2/km. However, current taxation systems in many EU Member States often fail to differentiate between high-emitting models and more efficient vehicles.
The report warns that freezing the UF correction would negatively impact the adoption of battery electric vehicles (BEVs). Estimates suggest such a move would lower BEV sales by 13 percentage points in 2030 and 18 percentage points by 2035.
