A Fraunhofer Institute study of nearly one million European vehicles found that plug-in hybrids (PHEVs) consume three to four times more fuel than official ratings suggest. [1, 2, 7] These vehicles produce significantly higher CO2 emissions in real-world conditions than testing models indicate. [1, 2, 7]
Research reveals that drivers charge their vehicles far less frequently than assumed, causing a heavy reliance on gasoline engines. [3, 6] These findings question the effectiveness of PHEVs as a bridge technology and may pressure regulators to revise emissions rules and subsidy programs. [3, 5]
Owners of mass-market brands including Kia, Toyota, and Ford charged their vehicles more often than luxury brand owners. [2, 4, 14] Porsche models recorded the lowest charging frequency and the highest fuel consumption in the study. [2, 4, 14]