EU study finds plug-in hybrids emit six times more pollution in real-world driving than tests suggest

Transport & Environment, using EU OBFCM data from about 220,000 PHEVs, reports real-world emissions for plug-in hybrids rose from 138 gCO2/km in 2023 to 145 gCO2/km in 2024—about 14% cleaner than the average fossil-fuel car, but six times dirtier in real driving than tests indicate. The widening gap is driven by utility factors that understate electric-mode use because many drivers don’t plug in, and automakers have lobbied to weaken updates to these factors. OBFCM data enables better real-world monitoring, underscoring that true pollution impacts depend on actual driving behavior, not lab results; if more drivers plugged in, PHEVs could be meaningfully cleaner, while current trends show the opposite due to policy and consumer habits.