🔗 Share this article

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

Growing Discrepancy Between Lab and Actual Emissions

Data reveals that PHEVs release only one-fifth lower CO₂ than traditional petrol and diesel cars, based on analysis conducted by a advocacy organization. That contrasts significantly with lab estimates, which assumed a 75% reduction in emissions.

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

“Actual emissions are increasing, while official figures are falling,” stated a senior analyst involved in the study. “This gap is widening and creates a serious issue. Consequently, PHEVs pollute almost as heavily as gasoline vehicles.”

Key Reasons Behind the Emissions Gap

Researchers attributed the majority of the difference to overestimates of the “utility factor” – the ratio of miles travelled in battery power relative to overall mileage. They found that only a quarter of travel was done in EV mode, whereas official estimates suggested 84%.

Additionally, when operating in electric mode, emission levels were well above lab projections. That happened because electric motors were insufficiently powerful sufficient to operate independently, leading to combustion motors burning gasoline for nearly one-third of the distance covered in electric mode.

Regulatory and Economic Implications

According to estimates, the underestimation of PHEV CO2 output allowed four major carmaker companies to escape over €5bn in penalties from 2021 and 2023, by falsely simplifying compliance with European Union fleet-average CO₂ targets.

Furthermore, owners of PHEVs would pay approximately €500 more per year in running expenses than would be estimated under lab tests.

“The strong statements that automakers often promote about their plug-in hybrid cars are clearly way off the truth,” stated a transport expert. “Consumers are being duped into thinking that by purchasing a PHEV, they are helping the environment and cutting costs. In reality, PHEVs are only slightly better than regular petrol and diesel cars in terms of energy use, CO₂ production, and running expenses.”

Policy Discussion and Industry Pressure

Hybrid vehicles have recently been drawn again into political debates as automakers have lobbied the EU to weaken CO₂ targets. A planned ban on new combustion engine vehicles in 2035 has faced intense pressure from the automotive industry and opposition from EU countries with significant car manufacturing.

Several senior politicians have suggested PHEVs as a possible “flexibility” option to include in the legislation.

An independent energy policy specialist, who was unaffiliated with the study, described the report a “very useful addition” after a long period in which segments of the automotive industry claimed there was too little information to accurately assess real-world CO2 output.

“The results demonstrate, without question, that the gap in official and real-world PHEV fuel consumption and CO₂ output is much, much greater than for petrol or diesel vehicles,” the expert said. “All policy changes concerning PHEVs should be implemented with utmost care and in the light of this evidence.”