Plug-in Hybrid electric Cars Pollute Nearly as Heavily as Gasoline Vehicles, Report Reveals

Plug-in hybrid electric vehicles release nearly 5x greater global warming pollution than official data show, as per a recent report.

Widening Gap In Lab and Actual Emissions

Statistics reveals that PHEVs release only 19% less CO₂ than traditional petrol and diesel cars, based on analysis conducted by a non-profit group. That differs significantly with laboratory tests, which assumed a three-quarters decrease in pollution.

Researchers studied data from onboard energy use monitors of eight hundred thousand cars sold in the EU from 2021 and 2023. The team discovered that actual CO₂ output from PHEVs in 2023 were 4.9 times greater than official estimates, up from 3.5 times in 2021.

“Real-world CO2 output are increasing, while lab-reported figures are falling,” said a senior researcher participating in the study. “That discrepancy is growing and poses a serious problem. As a result, PHEVs emit almost as heavily as petrol cars.”

Primary Factors Driving the Discrepancy

Analysts attributed most of the gap to overestimates of the “electric driving share” – the ratio of miles travelled in battery power relative to overall distance. They found that only a quarter of driving was completed in electric mode, while official estimates suggested 84%.

Additionally, when running in electric mode, pollution amounts were well above official estimates. That occurred because electric motors were not strong enough to function alone, leading to combustion motors using fossil fuels for almost a third of the distance covered in EV mode.

Regulatory and Financial Implications

According to estimates, the lowballing of PHEV CO2 output enabled four major carmaker groups to escape more than €5bn in fines between 2021 and 2023, by falsely simplifying adherence with EU fleet-average CO₂ targets.

Furthermore, drivers of PHEVs could pay approximately €500 extra annually in operating costs than is estimated under lab tests.

“The bold statements that automakers like to make about their PHEV vehicles are obviously way off the truth,” stated a transport analyst. “Consumers are being duped into thinking that by buying a PHEV, they are benefiting the planet and cutting money. Actually, PHEVs are only slightly improved than standard petrol and diesel vehicles in terms of fuel consumption, CO₂ emissions, and running expenses.”

Political Discussion and Automotive Pressure

Hybrid cars have lately been drawn back into policy debates as carmakers have lobbied the European Union to relax CO₂ targets. A proposed ban on new combustion engine vehicles in 2035 has faced heavy lobbying from the car sector and opposition from member states with significant car industries.

Some high-level officials have proposed PHEVs as a potential “flexibility” option to introduce in the regulation.

One independent energy economics expert, who was unaffiliated with the study, called the analysis a “highly valuable contribution” after a long period in which parts of the automotive sector argued there was too little data to accurately assess real-world CO2 output.

“The results show, beyond any doubt, that the difference in official and actual PHEV fuel consumption and CO₂ emissions is much, much greater than for gasoline or diesel cars,” the expert said. “All regulatory changes regarding PHEVs should be made with extreme care and considering that evidence.”