🔗 Share this article

Plug-in hybrid cars produce almost 5x greater global warming emissions than official figures indicate, as per a new analysis.

Growing Gap In Lab and Actual CO2 Output

Statistics shows that PHEVs emit only one-fifth lower CO₂ than conventional gas and diesel cars, according to analysis conducted by a non-profit organization. That differs sharply with laboratory estimates, which suggested a three-quarters decrease in pollution.

Researchers studied data from onboard energy use meters of eight hundred thousand cars registered in the EU between 2021 and 2023. The team found that real-world CO₂ emissions from PHEVs in 2023 were 4.9 times greater than official figures, up from three and a half times in 2021.

“Actual CO2 output are rising, while lab-reported emissions are falling,” stated a lead researcher participating in the study. “This gap is growing and poses a significant problem. Consequently, PHEVs emit almost as heavily as petrol vehicles.”

Primary Factors Behind the Emissions Gap

Researchers attributed most of the gap to inflated estimates of the “utility factor” – the ratio of miles driven in electric mode compared to total distance. The team found that only a quarter of travel was done in EV mode, whereas lab assumptions suggested 84%.

Even, when operating in EV mode, pollution levels were well above lab estimates. That occurred because electric motors were insufficiently powerful sufficient to operate alone, leading to combustion motors using fossil fuels for almost a third of the travel covered in EV mode.

Policy and Economic Implications

According to calculations, the underestimation of PHEV emissions enabled several major carmaker groups to escape more than €5bn in penalties from 2021 and 2023, by artificially easing compliance with European Union average fleet CO₂ targets.

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

“The bold claims that automakers like to make about their PHEV vehicles are obviously far from the mark,” commented a transport analyst. “Consumers are being duped into believing that by purchasing a PHEV, they are helping the environment and saving money. In reality, PHEVs are only slightly better than standard gas and diesel vehicles in terms of energy use, CO₂ production, and operating expenses.”

Political Discussion and Automotive Lobbying

Hybrid vehicles have recently been brought again into political discussions as carmakers have lobbied the European Union to weaken CO₂ standards. A planned prohibition on sales of new internal combustion vehicles in 2035 has faced intense pressure from the automotive sector and opposition from EU countries with large car manufacturing.

Several high-level politicians have proposed PHEVs as a potential “flexibility” option to include in the regulation.

An independent energy economics expert, who was unaffiliated with the study, described the analysis a “very useful addition” after years in which segments of the car sector argued there was too little information to accurately evaluate real-world CO2 output.

“The results show, beyond any doubt, that the difference between lab and actual PHEV energy use and CO₂ output is much, much larger than for gasoline or conventional cars,” the expert said. “All regulatory adjustments regarding PHEVs should be made with extreme caution and considering that data.”