Plug in Hybrid electric Vehicles Pollute Nearly as Much as Petrol Vehicles, Report Reveals

Plug-in hybrid cars produce nearly five times greater planet-heating emissions than official data indicate, according to a new report.

Growing Discrepancy In Official and Real-World Emissions

Statistics shows that PHEVs emit only one-fifth less CO₂ than conventional petrol and diesel vehicles, according to research carried out by a advocacy organization. That differs sharply with lab estimates, which suggested a three-quarters reduction in emissions.

Analysts examined data from in-vehicle energy use meters of eight hundred thousand cars registered in Europe between 2021 and 2023. They found that real-world CO₂ emissions from PHEVs in 2023 were 4.9 times higher than lab estimates, increased from 3.5 times in 2021.

“Real-world CO2 output are rising, while official figures are decreasing,” said a lead researcher participating in the study. “This gap is growing and creates a significant problem. As a result, PHEVs pollute nearly as heavily as gasoline vehicles.”

Key Reasons Driving the Discrepancy

Researchers attributed the majority of the difference to inflated estimates of the “utility factor” – the ratio of miles travelled in battery power relative to total distance. They found that only a quarter of driving was done in EV mode, whereas official assumptions assumed 84%.

Additionally, when operating in EV mode, pollution levels were significantly higher than official projections. That happened because EV motors were insufficiently powerful enough to function alone, leading to engines burning fossil fuels for almost one-third of the travel completed in EV mode.

Regulatory and Economic Implications

According to calculations, the lowballing of PHEV emissions allowed several major automaker groups to avoid more than €5bn in fines between 2021 and 2023, by artificially simplifying adherence with EU average fleet CO₂ targets.

Furthermore, drivers of PHEVs could spend approximately €500 more per year in running costs than is estimated under lab conditions.

“The strong statements that automakers like to make about their PHEV cars are obviously way off the mark,” commented a transport analyst. “Buyers are being duped into believing that by purchasing a PHEV, they are helping the environment and saving costs. Actually, PHEVs are only slightly better than standard gas and diesel vehicles in terms of energy use, CO₂ emissions, and operating expenses.”

Political Discussion and Automotive Lobbying

Plug-in hybrid cars have recently been brought back into political debates as carmakers have pressed the European Union to weaken CO₂ standards. A planned ban on sales of new combustion engine cars in 2035 has faced heavy lobbying from the car sector and opposition from member states with large car industries.

Several senior politicians have proposed plug-in hybrids as a potential “compromise” option to include in the regulation.

One external energy economics specialist, who was unaffiliated with the research, described the report a “highly valuable contribution” after years in which segments of the car sector argued there was too little information to properly assess actual CO2 output.

“These findings demonstrate, without question, that the difference in official and real-world PHEV fuel consumption and CO₂ emissions is significantly greater than for petrol or diesel vehicles,” they said. “Any policy changes concerning PHEVs should be made with utmost caution and in the light of this evidence.”