🔗 Share this article

Plug-in hybrid electric vehicles produce nearly 5x greater planet-heating pollution than lab-reported figures indicate, as per a recent analysis.

Widening Discrepancy Between Lab and Real-World Emissions

Data shows that PHEVs emit only one-fifth less CO₂ than traditional petrol and diesel vehicles, according to research carried out by a non-profit organization. That contrasts significantly with laboratory tests, which assumed a 75% decrease in pollution.

Analysts examined information from onboard energy use monitors of eight hundred thousand cars sold in Europe from 2021 and 2023. They found that real-world CO₂ output from PHEVs in 2023 were nearly five times greater than lab figures, up from three and a half times in 2021.

“Real-world CO2 output are increasing, while lab-reported emissions are decreasing,” said a senior researcher participating in the study. “That discrepancy is growing and poses a significant problem. Consequently, PHEVs emit nearly as heavily as gasoline vehicles.”

Key Reasons Driving the Emissions Gap

Researchers attributed most of the difference to inflated estimates of the “utility factor” – the percentage of miles driven in electric power compared to total distance. They determined that just a quarter of driving was done in electric mode, whereas official estimates suggested 84%.

Even, when running in EV mode, emission amounts were significantly higher than official estimates. That occurred because electric motors were not strong sufficient to function alone, resulting to engines burning fossil fuels for almost a third of the distance covered in EV mode.

Regulatory and Economic Implications

According to calculations, the lowballing of PHEV CO2 output allowed several large automaker companies to escape more than €5bn in fines from 2021 and 2023, by falsely easing adherence with European Union average fleet CO₂ standards.

Additionally, owners of PHEVs could pay approximately €500 more annually in operating costs than would be estimated under laboratory conditions.

“The bold statements that automakers often promote about their PHEV cars are obviously far from the truth,” commented a automotive analyst. “Consumers are being duped into believing that by buying a PHEV, they are benefiting the planet and saving costs. Actually, PHEVs are little improved than regular petrol and diesel vehicles in terms of energy use, CO₂ production, and running costs.”

Political Debate and Industry Lobbying

Hybrid vehicles have lately been brought again into policy debates as carmakers have lobbied the EU to relax CO₂ standards. A proposed ban on new internal combustion vehicles in 2035 has faced intense pressure from the automotive sector and resistance from member states with large car industries.

Several high-level officials have suggested PHEVs as a potential “flexibility” solution to include in the legislation.

One independent energy policy expert, who was not involved with the research, described the analysis a “very useful addition” after years in which segments of the automotive sector claimed there was too little data to properly assess real-world emissions.

“The results demonstrate, without question, that the difference between official and real-world PHEV energy use and CO₂ emissions is significantly larger than for gasoline or diesel cars,” they stated. “All regulatory adjustments regarding PHEVs should be implemented with extreme care and considering that data.”