🔗 Share this article

PHEVs emit almost 5x more global warming emissions than lab-reported figures show, as per a new analysis.

Growing Gap Between Lab and Actual CO2 Output

Data reveals that PHEVs emit only 19% lower CO₂ than conventional gas and diesel cars, according to analysis conducted by a advocacy organization. This contrasts significantly with lab estimates, which assumed a 75% decrease in emissions.

Researchers studied information from onboard fuel consumption monitors of eight hundred thousand cars sold in Europe between 2021 and 2023. They discovered that real-world CO₂ emissions from PHEVs in 2023 were nearly five times greater than official figures, up from 3.5 times in 2021.

“Actual CO2 output are increasing, while lab-reported emissions are decreasing,” said a lead researcher involved in the study. “That discrepancy is widening and poses a serious problem. Consequently, PHEVs pollute nearly as heavily as gasoline cars.”

Primary Factors Behind the Discrepancy

Researchers attributed most of the difference to overestimates of the “utility factor” – the ratio of miles driven in electric mode compared to total distance. They found that only a quarter of travel was done in electric mode, while official assumptions suggested 84%.

Even, when operating in EV mode, pollution levels were significantly higher than official projections. This occurred because electric motors were insufficiently powerful sufficient to operate independently, leading to combustion motors burning fossil fuels for almost a third of the travel covered in EV mode.

Regulatory and Economic Implications

According to calculations, the lowballing of PHEV emissions allowed several large automaker companies to avoid more than €5bn in fines from 2021 and 2023, by artificially easing adherence with EU average fleet CO₂ standards.

Additionally, owners of PHEVs would spend approximately €500 more per year in running expenses than is assumed under laboratory tests.

“The bold claims that automakers often promote about their PHEV cars are clearly far from the mark,” commented a transport expert. “Buyers are being duped into believing that by buying a PHEV, they are benefiting the environment and cutting money. Actually, PHEVs are little improved than standard gas and diesel cars in terms of fuel use, CO₂ production, and running costs.”

Political Debate and Automotive Pressure

Plug-in hybrid cars have recently been brought again into policy debates as carmakers have pressed the EU to relax CO₂ targets. A proposed prohibition on sales of new internal combustion vehicles in 2035 has faced intense lobbying from the car sector and opposition from EU countries with large automotive industries.

Several senior politicians have suggested plug-in hybrids as a potential “compromise” solution to include in the legislation.

One independent energy policy expert, who was not involved with the research, described the analysis a “highly valuable contribution” after a long period in which segments of the automotive sector claimed there was insufficient information to accurately evaluate actual emissions.

“These findings show, without question, that the gap between lab and real-world PHEV energy use and CO₂ output is significantly greater than for gasoline or conventional vehicles,” they stated. “Any policy adjustments concerning PHEVs should be made with extreme care and in the light of that evidence.”