🔗 Share this article

Plug-in hybrid cars emit nearly 5x more global warming emissions than lab-reported figures indicate, as per a new report.

Widening Discrepancy In Official and Real-World Emissions

Statistics shows that PHEVs emit only 19% lower CO₂ than traditional gas and diesel cars, based on research conducted by a non-profit group. This contrasts sharply with lab estimates, which assumed a 75% decrease in emissions.

Analysts examined information from onboard energy use meters of eight hundred thousand vehicles sold in Europe from 2021 and 2023. They found that actual CO₂ output from PHEVs in 2023 were 4.9 times higher than official figures, up from 3.5 times in 2021.

“Real-world emissions are rising, while lab-reported figures are decreasing,” said a lead researcher involved in the report. “This discrepancy is widening and creates a significant problem. As a result, PHEVs emit nearly as much as petrol vehicles.”

Key Reasons Behind the Discrepancy

Researchers linked the majority of the gap to inflated estimates of the “utility factor” – the ratio of miles driven in electric power compared to total distance. They determined that just a quarter of travel was completed in EV mode, whereas lab estimates suggested 84%.

Additionally, when operating in electric mode, emission levels were well above official projections. This occurred because electric motors were not strong sufficient to operate independently, leading to engines using fossil fuels for almost a third of the distance covered in electric mode.

Regulatory and Economic Implications

According to calculations, the underestimation of PHEV CO2 output allowed several major automaker groups to avoid over €5bn in fines between 2021 and 2023, by artificially simplifying compliance with EU fleet-average CO₂ standards.

Additionally, drivers of PHEVs could pay approximately €500 more annually in running costs than is assumed under lab tests.

“The bold claims that manufacturers often promote about their PHEV cars are clearly way off the truth,” stated a automotive analyst. “Buyers are being duped into thinking that by buying a PHEV, they are helping the planet and saving money. Actually, PHEVs are little better than regular gas and diesel cars in terms of fuel use, CO₂ emissions, and operating expenses.”

Policy Debate and Automotive Lobbying

Plug-in hybrid cars have lately been brought again into policy discussions as automakers have pressed the European Union to weaken CO₂ standards. A planned prohibition on new internal combustion vehicles in 2035 has faced intense lobbying from the car industry and opposition from EU countries with large automotive industries.

Several senior officials have proposed plug-in hybrids as a possible “flexibility” option to introduce in the regulation.

One independent energy policy specialist, who was unaffiliated with the research, called the analysis a “very useful contribution” after years in which segments of the automotive industry claimed there was too little data to accurately assess real-world emissions.

“The results show, beyond any doubt, that the gap between lab and actual PHEV energy use and CO₂ output is much, much greater than for petrol or conventional vehicles,” the expert said. “Any regulatory adjustments concerning PHEVs should be made with utmost care and considering this evidence.”