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PHEVs emit nearly five times more global warming pollution than official figures show, as per a recent analysis.

Growing Discrepancy Between Lab and Actual CO2 Output

Statistics reveals that PHEVs release only one-fifth less CO₂ than traditional petrol and diesel cars, according to research carried out by a non-profit organization. This contrasts significantly with lab estimates, which assumed a three-quarters decrease in emissions.

Researchers examined data from in-vehicle energy use meters of eight hundred thousand cars registered in the EU between 2021 and 2023. The team found that real-world CO₂ output from PHEVs in 2023 were 4.9 times greater than official estimates, increased from 3.5 times in 2021.

“Real-world emissions are increasing, while lab-reported emissions are falling,” stated a lead researcher involved in the study. “That discrepancy is growing and poses a serious issue. Consequently, PHEVs emit almost as much as petrol vehicles.”

Key Reasons Behind the Emissions Gap

Researchers linked most of the difference to inflated estimates of the “electric driving share” – the ratio of miles travelled in battery power relative to overall distance. The team found that just a quarter of driving was done in electric mode, while official estimates assumed 84%.

Additionally, when running in electric mode, emission levels were significantly higher than official projections. That happened because EV motors were insufficiently powerful enough to operate alone, leading to engines burning fossil fuels for nearly a third of the travel completed in EV mode.

Regulatory and Economic Consequences

According to calculations, the underestimation of PHEV CO2 output allowed four major carmaker companies to escape more than €5bn in penalties between 2021 and 2023, by falsely simplifying adherence with European Union fleet-average CO₂ targets.

Additionally, drivers of PHEVs could pay approximately €500 more annually in running costs than is assumed under laboratory conditions.

“The bold statements that automakers like to make about their PHEV cars are obviously far from the mark,” stated a automotive analyst. “Consumers are being duped into thinking that by purchasing a PHEV, they are helping the environment and cutting money. Actually, PHEVs are little better than regular petrol and diesel cars in terms of fuel use, CO₂ emissions, and running expenses.”

Policy Debate and Industry Pressure

Hybrid vehicles have recently been drawn again into political debates as automakers have pressed the EU to relax CO₂ standards. A planned prohibition on sales of new combustion engine cars in 2035 has faced heavy lobbying from the car industry and opposition from EU countries with significant automotive industries.

Some senior politicians have proposed PHEVs as a potential “compromise” option to introduce in the regulation.

An independent energy economics expert, who was unaffiliated with the research, called the report a “very useful contribution” after years in which segments of the automotive industry claimed there was insufficient data to accurately evaluate real-world emissions.

“The results demonstrate, without question, that the gap between official and real-world PHEV fuel consumption and CO₂ output is significantly greater than for gasoline or diesel vehicles,” they said. “Any policy adjustments regarding PHEVs should be implemented with utmost care and considering that evidence.”