🔗 Share this article

Plug-in hybrid cars emit almost five times more global warming emissions than official data indicate, as per a recent analysis.

Growing Gap In Lab and Real-World CO2 Output

Statistics shows that PHEVs emit just 19% lower CO₂ than traditional petrol and diesel cars, according to research conducted by a non-profit organization. That differs significantly with lab estimates, which suggested a three-quarters reduction in emissions.

Analysts studied information from in-vehicle fuel consumption meters of 800,000 cars sold in Europe from 2021 and 2023. They discovered that actual CO₂ output from PHEVs in 2023 were nearly five times higher than lab figures, increased from three and a half times in 2021.

“Real-world CO2 output are increasing, while official figures are falling,” said a lead researcher involved in the study. “This gap is growing and poses a serious problem. As a result, PHEVs emit nearly as heavily as petrol cars.”

Primary Reasons Driving the Emissions Gap

Researchers linked most of the gap to overestimates of the “electric driving share” – the ratio of miles driven in electric power relative to total mileage. They found that just 27% of driving was done in EV mode, whereas lab assumptions suggested 84%.

Additionally, when operating in EV mode, emission levels were significantly higher than official projections. That happened because EV motors were not strong enough to function independently, leading to engines burning gasoline for nearly a third of the travel completed in electric mode.

Policy and Financial Implications

Based on estimates, the underestimation of PHEV CO2 output enabled four major automaker companies to avoid more than €5bn in fines from 2021 and 2023, by falsely easing adherence with EU average fleet CO₂ standards.

Furthermore, owners of PHEVs could spend about €500 extra annually in running costs than is assumed under lab tests.

“The bold statements that automakers like to make about their plug-in hybrid vehicles are obviously far from the truth,” stated a transport expert. “Consumers are being misled into thinking that by purchasing a PHEV, they are benefiting the planet and saving money. In reality, PHEVs are only slightly better than regular petrol and diesel vehicles in terms of energy use, CO₂ production, and running expenses.”

Policy Discussion and Automotive Lobbying

Plug-in hybrid cars have lately been drawn again into political debates as automakers have lobbied the European Union to weaken CO₂ standards. A proposed prohibition on new internal combustion vehicles in 2035 has faced intense pressure from the car industry and opposition from member states with large car manufacturing.

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

An independent energy economics specialist, who was not involved with the research, called the report a “very useful addition” after years in which segments of the car industry argued there was too little data to accurately assess real-world CO2 output.

“The results show, without question, that the gap in official and real-world PHEV energy use and CO₂ emissions is much, much larger than for petrol or conventional vehicles,” they stated. “All policy adjustments regarding PHEVs should be implemented with utmost care and considering this evidence.”