🔗 Share this article

PHEVs release almost 5x greater global warming emissions than official figures indicate, according to a recent report.

Growing Discrepancy In Official and Real-World Emissions

Statistics shows that PHEVs release only 19% lower CO₂ than conventional petrol and diesel cars, based on analysis conducted by a non-profit group. That differs significantly with lab tests, which assumed a three-quarters reduction in emissions.

Analysts examined information from onboard energy use monitors of 800,000 vehicles sold in the EU from 2021 and 2023. They found that real-world CO₂ emissions from PHEVs in 2023 were nearly five times greater than lab figures, increased from 3.5 times in 2021.

“Real-world CO2 output are rising, while official emissions are decreasing,” stated a lead analyst involved in the study. “That gap is growing and creates a serious issue. As a result, PHEVs pollute nearly as much as gasoline cars.”

Key Reasons Driving the Discrepancy

Researchers attributed the majority of the difference to inflated estimates of the “utility factor” – the ratio of miles driven in electric mode relative to total distance. They determined that only a quarter of driving was completed in electric mode, while lab assumptions assumed 84%.

Even, when running in electric mode, pollution amounts were well above lab estimates. That happened because electric motors were insufficiently powerful enough to function alone, resulting to combustion motors using gasoline for nearly a third of the distance covered in EV mode.

Regulatory and Financial Implications

According to calculations, the underestimation of PHEV emissions enabled four large automaker groups to escape more than €5bn in fines from 2021 and 2023, by artificially easing adherence with European Union fleet-average CO₂ standards.

Furthermore, owners of PHEVs could spend about €500 extra per year in operating expenses than would be estimated under laboratory conditions.

“The bold claims that manufacturers like to make about their plug-in hybrid vehicles are obviously way off the truth,” commented a automotive analyst. “Consumers are being duped into thinking that by purchasing a PHEV, they are benefiting the planet and cutting costs. Actually, PHEVs are only slightly improved than regular gas and diesel vehicles in terms of energy use, CO₂ production, and operating costs.”

Political Debate and Automotive Lobbying

Hybrid vehicles have recently been brought again into political debates as automakers have pressed the European Union to relax CO₂ standards. A planned ban on new internal combustion vehicles in 2035 has faced intense lobbying from the automotive industry and opposition from member states with large automotive manufacturing.

Some senior officials have proposed plug-in hybrids as a possible “flexibility” solution to include in the regulation.

One independent energy policy expert, who was unaffiliated with the study, called the analysis a “very useful addition” after a long period in which parts of the automotive industry claimed there was insufficient information to properly assess actual emissions.

“The results demonstrate, without question, that the difference between official and real-world PHEV energy use and CO₂ emissions is much, much larger than for gasoline or conventional vehicles,” the expert said. “Any policy adjustments regarding PHEVs should be implemented with utmost care and in the light of that evidence.”