🔗 Share this article

Plug-in hybrid electric vehicles produce nearly five times greater global warming emissions than official figures indicate, as per a new analysis.

Growing Discrepancy In Lab and Real-World CO2 Output

Data shows that PHEVs release only 19% lower CO₂ than traditional petrol and diesel vehicles, based on research carried out by a advocacy organization. That contrasts significantly with laboratory estimates, which assumed a three-quarters reduction in pollution.

Analysts examined information from onboard fuel consumption meters of eight hundred thousand cars sold in Europe from 2021 and 2023. They found that actual CO₂ emissions from PHEVs in 2023 were nearly five times higher than official figures, increased from three and a half times in 2021.

“Real-world emissions are rising, while official emissions are falling,” said a senior analyst involved in the report. “This discrepancy is widening and poses a serious issue. Consequently, PHEVs pollute nearly as much as petrol cars.”

Key Factors Driving the Discrepancy

Researchers linked most of the gap to overestimates of the “utility factor” – the percentage of kilometers travelled in electric mode compared to total mileage. They found that only 27% of driving was completed in EV mode, while lab assumptions suggested 84%.

Additionally, when operating in EV mode, emission levels were well above official estimates. That happened because EV motors were insufficiently powerful enough to operate alone, leading to engines burning fossil fuels for almost one-third of the distance completed in EV mode.

Regulatory and Economic Consequences

According to estimates, the underestimation of PHEV CO2 output allowed four large carmaker groups to avoid more than €5bn in fines from 2021 and 2023, by artificially simplifying compliance with EU average fleet CO₂ targets.

Furthermore, drivers of PHEVs could pay about €500 extra annually in operating expenses than is assumed under laboratory tests.

“The strong statements that automakers like to make about their PHEV vehicles are obviously way off the truth,” stated a automotive expert. “Consumers are being misled into believing that by purchasing a PHEV, they are benefiting the planet and saving costs. Actually, PHEVs are little better than standard gas and diesel vehicles in terms of fuel consumption, CO₂ emissions, and operating costs.”

Political Debate and Industry Lobbying

Plug-in hybrid vehicles have recently been brought again into political discussions as carmakers have lobbied the European Union to weaken CO₂ targets. A planned ban on sales of new internal combustion vehicles in 2035 has faced intense lobbying from the car sector and resistance from member states with large automotive industries.

Some high-level officials have proposed plug-in hybrids as a potential “flexibility” solution to include in the regulation.

One external energy economics expert, who was unaffiliated with the research, described the analysis a “very useful addition” after a long period in which parts of the car sector claimed there was too little data to accurately assess real-world emissions.

“These findings demonstrate, without question, that the difference in lab and actual PHEV energy use and CO₂ emissions is significantly larger than for petrol or conventional vehicles,” the expert said. “All policy changes regarding PHEVs should be made with extreme caution and in the light of this data.”