Study finds plug‑in hybrids consume up to three times official estimates

A Fraunhofer Institute study in Karlsruhe examined real‑world data from 981,000 plug‑in hybrid vehicles operating in Germany. The analysis showed that, on average, these cars use up to 300 % more fuel than the values recorded in the WLTP homologation cycle, resulting in significantly higher CO₂ emissions.

The excess consumption is linked to early‑generation models, owners who rarely recharge the battery, and the additional weight of the battery packs. The findings have prompted scrutiny of fiscal incentives introduced in the 2025 budget law that favored PHEVs over full hybrids, and manufacturers are now developing “Super Hybrid” architectures to improve efficiency when the vehicle is not plugged in.