🔗 Share this article

PHEVs emit almost five times greater planet-heating pollution than lab-reported figures indicate, as per a recent analysis.

Growing Gap Between Official and Actual Emissions

Data shows that PHEVs emit just one-fifth lower CO₂ than traditional gas and diesel vehicles, according to analysis carried out by a non-profit group. This differs sharply with lab tests, which suggested a three-quarters decrease in pollution.

Researchers studied information from onboard energy use meters of 800,000 cars registered in Europe from 2021 and 2023. The team found that real-world CO₂ emissions from PHEVs in 2023 were 4.9 times greater than lab estimates, increased from three and a half times in 2021.

“Real-world emissions are rising, while official emissions are falling,” stated a lead researcher involved in the study. “This gap is widening and creates a significant problem. As a result, PHEVs pollute nearly as much as gasoline vehicles.”

Primary Reasons Behind the Discrepancy

Researchers linked most of the gap to overestimates of the “utility factor” – the ratio of kilometers driven in battery mode compared to overall distance. The team determined that only 27% of travel was completed in electric mode, while lab estimates assumed 84%.

Even, when running in electric mode, emission amounts were significantly higher than official projections. That occurred because EV motors were not strong sufficient to operate alone, resulting to engines burning gasoline for nearly a third of the travel covered in electric mode.

Regulatory and Economic Implications

According to estimates, the lowballing of PHEV CO2 output enabled several major carmaker groups to avoid over €5bn in fines from 2021 and 2023, by falsely simplifying compliance with European Union average fleet CO₂ targets.

Furthermore, owners of PHEVs would spend about €500 extra annually in running expenses than would be assumed under laboratory tests.

“The strong statements that manufacturers often promote about their plug-in hybrid vehicles are clearly way off the mark,” commented a automotive analyst. “Consumers are being misled into thinking that by purchasing a PHEV, they are benefiting the environment and cutting money. In reality, PHEVs are only slightly improved than standard gas and diesel vehicles in terms of fuel use, CO₂ production, and operating costs.”

Policy Discussion and Automotive Lobbying

Hybrid vehicles have lately been brought back into political discussions as automakers have lobbied the EU to weaken CO₂ standards. A proposed ban on new internal combustion vehicles in 2035 has faced heavy pressure from the car industry and resistance from member states with large car industries.

Several high-level politicians have proposed PHEVs as a possible “compromise” solution to introduce in the regulation.

One external energy economics expert, who was not involved with the study, called the report a “very useful contribution” after a long period in which segments of the automotive industry argued there was insufficient information to properly assess real-world emissions.

“These findings show, beyond any doubt, that the gap in official and actual PHEV energy use and CO₂ output is significantly greater than for petrol or conventional vehicles,” they said. “All regulatory changes regarding PHEVs should be made with utmost care and in the light of this data.”