🔗 Share this article

Plug-in hybrid electric vehicles release nearly 5x greater planet-heating pollution than official figures show, as per a recent analysis.

Growing Discrepancy In Official and Actual Emissions

Data reveals that PHEVs emit just one-fifth less CO₂ than conventional gas and diesel cars, according to analysis conducted by a non-profit organization. That contrasts significantly with laboratory tests, which suggested a three-quarters decrease in pollution.

Analysts studied data from in-vehicle fuel consumption meters of 800,000 vehicles sold in the EU between 2021 and 2023. They discovered that real-world CO₂ output from PHEVs in 2023 were 4.9 times higher than official figures, increased from three and a half times in 2021.

“Real-world emissions are rising, while lab-reported figures are falling,” stated a lead researcher involved in the report. “That gap is widening and creates a serious problem. Consequently, PHEVs pollute nearly as heavily as gasoline cars.”

Primary Reasons Behind the Discrepancy

Researchers attributed the majority of the difference to overestimates of the “electric driving share” – the percentage of miles driven in electric mode compared to total distance. The team found that only a quarter of driving was done in electric mode, while official estimates suggested over four-fifths.

Even, when operating in electric mode, pollution amounts were well above official estimates. This occurred because electric motors were not strong enough to operate alone, resulting to combustion motors burning gasoline for almost one-third of the travel completed in electric mode.

Policy and Economic Implications

According to estimates, the underestimation of PHEV CO2 output allowed several large carmaker groups to avoid over €5bn in fines from 2021 and 2023, by artificially simplifying adherence with EU fleet-average CO₂ standards.

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

“The strong claims that manufacturers like to make about their PHEV vehicles are obviously way off the mark,” stated a transport expert. “Consumers are being duped into believing that by purchasing a PHEV, they are helping the planet and cutting costs. In reality, PHEVs are little improved than standard petrol and diesel vehicles in terms of energy consumption, CO₂ emissions, and running expenses.”

Political Discussion and Automotive Pressure

Plug-in hybrid cars have recently been brought again into policy discussions as carmakers have lobbied the EU to weaken CO₂ targets. A proposed prohibition on sales of new combustion engine vehicles in 2035 has faced intense lobbying from the car industry and opposition from member states with significant car manufacturing.

Some senior politicians have proposed plug-in hybrids as a potential “flexibility” option to introduce in the legislation.

One external energy economics expert, who was not involved with the study, called the analysis a “very useful addition” after a long period in which parts of the car sector claimed there was too little information to accurately assess actual emissions.

“The results demonstrate, without question, that the gap between official and actual PHEV fuel consumption and CO₂ emissions is much, much greater than for gasoline or diesel cars,” the expert said. “Any policy adjustments regarding PHEVs should be made with utmost care and considering that data.”