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PHEVs emit nearly five times greater planet-heating emissions than official figures show, as per a recent analysis.

Widening Gap Between Lab and Real-World CO2 Output

Statistics shows that PHEVs release just one-fifth lower CO₂ than conventional petrol and diesel vehicles, based on research conducted by a advocacy group. This differs sharply with laboratory tests, which assumed a three-quarters reduction in pollution.

Analysts examined information from in-vehicle fuel consumption meters of eight hundred thousand vehicles sold in the EU between 2021 and 2023. The team found that real-world CO₂ output from PHEVs in 2023 were nearly five times greater than lab figures, increased from three and a half times in 2021.

“Real-world CO2 output are rising, while lab-reported figures are falling,” said a senior researcher participating in the report. “This gap is growing and poses a serious problem. As a result, PHEVs emit nearly as heavily as gasoline cars.”

Primary Factors Behind the Emissions Gap

Researchers linked most of the difference to inflated estimates of the “utility factor” – the ratio of kilometers driven in electric power compared to total distance. They found that only 27% of driving was completed in electric mode, whereas lab assumptions suggested 84%.

Even, when operating in electric mode, pollution amounts were significantly higher than official projections. That happened because EV motors were insufficiently powerful enough to operate independently, leading to combustion motors using fossil fuels for nearly one-third of the distance completed in electric mode.

Regulatory and Financial Implications

According to calculations, the lowballing of PHEV CO2 output enabled several major carmaker groups to avoid more than €5bn in penalties between 2021 and 2023, by falsely simplifying adherence with European Union fleet-average CO₂ targets.

Additionally, owners of PHEVs could pay about €500 more annually in operating expenses than is assumed under laboratory tests.

“The bold statements that automakers often promote about their PHEV vehicles are obviously way off the truth,” stated a transport analyst. “Consumers are being duped into thinking that by buying a PHEV, they are helping the planet and cutting costs. Actually, PHEVs are only slightly better than standard gas and diesel cars in terms of energy use, CO₂ production, and operating expenses.”

Policy Debate and Industry Lobbying

Plug-in hybrid vehicles have lately been brought back into policy discussions as automakers have lobbied the European Union to relax CO₂ targets. A planned prohibition on new combustion engine vehicles in 2035 has faced intense lobbying from the automotive industry and resistance from EU countries with significant automotive industries.

Some senior officials have proposed PHEVs as a potential “flexibility” solution to include in the legislation.

One external energy policy expert, who was not involved with the study, described the report a “highly valuable contribution” after years in which parts of the car industry claimed there was too little data to accurately evaluate actual emissions.

“The results demonstrate, without question, that the difference in official and real-world PHEV energy use and CO₂ emissions is much, much greater than for gasoline or diesel vehicles,” they said. “Any policy changes concerning PHEVs should be implemented with extreme caution and considering this evidence.”