🔗 Share this article

Plug-in hybrid electric vehicles produce almost 5x more planet-heating emissions than official figures show, according to a new analysis.

Widening Discrepancy In Official and Real-World Emissions

Statistics shows that PHEVs release just one-fifth less CO₂ than conventional petrol and diesel vehicles, according to research carried out by a advocacy group. That differs significantly with lab estimates, which assumed a three-quarters reduction in emissions.

Researchers examined data from in-vehicle fuel consumption meters of eight hundred thousand vehicles registered in the EU between 2021 and 2023. They found that actual CO₂ emissions 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 rising, while lab-reported emissions are falling,” stated a senior researcher participating in the report. “This discrepancy is widening and creates a significant problem. As a result, PHEVs emit nearly as much as gasoline vehicles.”

Primary Reasons Behind the Discrepancy

Analysts attributed most of the gap to overestimates of the “utility factor” – the percentage of miles travelled in battery power compared to total distance. The team found that only a quarter of travel was completed in EV mode, whereas official assumptions assumed over four-fifths.

Even, when operating in EV mode, pollution levels were well above lab estimates. That occurred because electric motors were not strong sufficient to operate alone, leading to combustion motors using fossil fuels for nearly a third of the distance completed in electric mode.

Policy and Financial Implications

According to estimates, the lowballing of PHEV emissions allowed four major carmaker companies to escape more than €5bn in fines from 2021 and 2023, by artificially easing compliance with European Union average fleet CO₂ targets.

Additionally, owners of PHEVs could spend approximately €500 extra per year in operating costs than is estimated under laboratory tests.

“The bold statements that automakers like to make about their PHEV vehicles are obviously far from the mark,” stated a automotive expert. “Consumers are being duped into thinking that by purchasing a PHEV, they are helping the environment and cutting costs. Actually, PHEVs are little improved than standard petrol and diesel cars in terms of energy use, CO₂ emissions, and operating costs.”

Political Discussion and Automotive Pressure

Plug-in hybrid cars have recently been drawn again into political debates as automakers have pressed the European Union to weaken CO₂ targets. A planned prohibition on sales of new internal combustion cars in 2035 has faced heavy lobbying from the automotive industry and resistance from member states with large automotive manufacturing.

Some senior officials have proposed plug-in hybrids as a potential “compromise” solution to introduce in the legislation.

An external energy economics specialist, who was unaffiliated with the study, called the analysis a “very useful addition” after years in which segments of the car sector claimed there was insufficient information to accurately evaluate real-world CO2 output.

“These findings show, beyond any doubt, that the gap between official and actual PHEV energy use and CO₂ emissions is significantly larger than for petrol or diesel vehicles,” the expert stated. “Any policy adjustments regarding PHEVs should be made with utmost caution and considering this evidence.”