🔗 Share this article

Plug-in hybrid electric vehicles produce almost five times greater global warming emissions than official figures show, as per a new analysis.

Growing Gap Between Lab and Actual Emissions

Data reveals that PHEVs emit just one-fifth lower CO₂ than traditional gas and diesel vehicles, according to research conducted by a non-profit organization. That contrasts significantly with laboratory estimates, which suggested a 75% decrease in pollution.

Researchers examined information from onboard fuel consumption monitors of eight hundred thousand vehicles sold in the EU from 2021 and 2023. The team found that actual CO₂ output from PHEVs in 2023 were nearly five times higher than lab figures, up from 3.5 times in 2021.

“Real-world emissions are increasing, while official figures are falling,” stated a lead analyst participating in the study. “This gap is widening and creates a serious issue. As a result, PHEVs emit almost as heavily as petrol vehicles.”

Key Reasons Behind the Emissions Gap

Analysts linked the majority of the difference to overestimates of the “utility factor” – the ratio of miles driven in electric mode relative to total distance. They determined that just a quarter of travel was done in electric mode, whereas official assumptions suggested over four-fifths.

Even, when running in electric mode, pollution amounts were significantly higher than lab projections. That occurred because EV motors were not strong sufficient to function independently, leading to engines burning fossil fuels for almost one-third of the travel completed in EV mode.

Regulatory and Financial Consequences

Based on estimates, the underestimation of PHEV CO2 output allowed several major automaker companies to avoid over €5bn in fines from 2021 and 2023, by falsely easing adherence with European Union fleet-average CO₂ targets.

Furthermore, drivers of PHEVs could pay about €500 extra annually in running expenses than would be assumed under lab conditions.

“The strong statements that manufacturers like to make about their plug-in hybrid cars are clearly way off the truth,” commented a transport expert. “Buyers are being misled into believing that by purchasing a PHEV, they are benefiting the environment and saving costs. In reality, PHEVs are little improved than regular gas and diesel vehicles in terms of fuel consumption, CO₂ emissions, and running expenses.”

Policy Discussion and Industry Pressure

Hybrid cars have recently been brought again into political discussions as carmakers have lobbied the EU to weaken CO₂ standards. A proposed prohibition on new combustion engine vehicles in 2035 has faced intense lobbying from the automotive sector and resistance from EU countries with large automotive industries.

Some senior politicians have proposed PHEVs as a possible “flexibility” option to introduce in the legislation.

One independent energy policy expert, who was unaffiliated with the study, called the analysis a “highly valuable contribution” after years in which segments of the automotive sector argued there was too little information to accurately evaluate actual emissions.

“These findings show, without question, that the difference between official and real-world PHEV fuel consumption and CO₂ emissions is much, much larger than for gasoline or diesel cars,” the expert stated. “All policy changes regarding PHEVs should be implemented with utmost caution and in the light of this data.”