🔗 Share this article

Plug-in hybrid cars emit almost 5x more planet-heating emissions than official data show, as per a recent analysis.

Widening Gap Between Lab and Real-World Emissions

Data shows that PHEVs release just 19% less CO₂ than traditional gas and diesel cars, according to analysis conducted by a non-profit organization. That contrasts sharply with laboratory estimates, which assumed a 75% decrease in pollution.

Researchers examined data from onboard fuel consumption meters of 800,000 cars sold in the EU between 2021 and 2023. The team discovered that real-world CO₂ emissions from PHEVs in 2023 were 4.9 times higher than official figures, increased from three and a half times in 2021.

“Real-world emissions are increasing, while official emissions are falling,” stated a lead researcher involved in the report. “That discrepancy is widening and poses a significant issue. As a result, PHEVs emit almost as heavily as petrol cars.”

Primary Reasons Behind the Discrepancy

Researchers attributed the majority of the gap to inflated estimates of the “utility factor” – the ratio of miles driven in electric mode relative to total distance. The team found that just 27% of driving was done in electric mode, whereas lab assumptions suggested over four-fifths.

Even, when operating in electric mode, emission levels were well above lab projections. This occurred because EV motors were insufficiently powerful sufficient to function alone, leading to engines using fossil fuels for nearly a third of the distance completed in electric mode.

Policy and Financial Consequences

According to calculations, the lowballing of PHEV CO2 output allowed several major carmaker groups to avoid more than €5bn in penalties between 2021 and 2023, by artificially simplifying compliance with EU average fleet CO₂ standards.

Additionally, drivers of PHEVs would spend about €500 more annually in operating expenses than is assumed under laboratory tests.

“The bold statements that manufacturers like to make about their plug-in hybrid cars are obviously way off the mark,” commented a transport expert. “Consumers are being duped into thinking that by buying a PHEV, they are benefiting the planet and saving costs. Actually, PHEVs are only slightly better than standard petrol and diesel vehicles in terms of energy use, CO₂ production, and running costs.”

Political Discussion and Automotive Lobbying

Hybrid cars have recently been brought back into policy discussions as carmakers have lobbied the European Union to weaken CO₂ standards. A proposed ban on new combustion engine cars in 2035 has faced heavy lobbying from the car sector and resistance from EU countries with large car manufacturing.

Several high-level politicians have suggested plug-in hybrids as a possible “compromise” option to include in the regulation.

An external energy policy specialist, who was not involved with the research, called the report a “very useful contribution” after a long period in which segments of the automotive sector claimed there was insufficient data to properly assess actual emissions.

“The results demonstrate, without question, that the gap between official and real-world PHEV fuel consumption and CO₂ emissions is significantly larger than for petrol or conventional vehicles,” the expert said. “All regulatory changes concerning PHEVs should be implemented with extreme care and considering that evidence.”