Plug in Hybrid electric Vehicles Emit Nearly as Heavily as Petrol Cars, Report Reveals

Plug-in hybrid cars produce almost five times more global warming emissions than official figures indicate, according to a recent report.

Widening Gap Between Official and Real-World CO2 Output

Data reveals that PHEVs emit just one-fifth lower CO₂ than conventional gas and diesel vehicles, according to research carried out by a advocacy organization. That differs sharply with laboratory tests, which assumed a 75% decrease in emissions.

Researchers studied data from onboard fuel consumption meters of 800,000 vehicles sold in Europe from 2021 and 2023. They discovered that real-world CO₂ output from PHEVs in 2023 were 4.9 times higher than lab figures, increased from three and a half times in 2021.

“Actual CO2 output are rising, while lab-reported figures are decreasing,” said a senior analyst involved in the report. “That discrepancy is growing and creates a serious problem. As a result, PHEVs emit almost as heavily as gasoline vehicles.”

Key Reasons Behind the Emissions Gap

Analysts attributed the majority of the difference to inflated estimates of the “electric driving share” – the percentage of kilometers driven in battery mode compared to total distance. They found that just a quarter of driving was done in electric mode, while lab assumptions suggested 84%.

Even, when operating in electric mode, emission levels were significantly higher than official estimates. This occurred because electric motors were not strong sufficient to operate independently, leading to engines burning fossil fuels for almost a third of the travel covered in electric mode.

Policy and Financial Implications

According to calculations, the underestimation of PHEV emissions allowed four major automaker companies to escape over €5bn in penalties between 2021 and 2023, by falsely simplifying compliance with EU average fleet CO₂ targets.

Furthermore, owners of PHEVs could pay approximately €500 more per year in operating expenses than would be assumed under laboratory tests.

“The bold claims that manufacturers often promote about their PHEV cars are obviously far from the mark,” stated a transport expert. “Consumers are being duped into thinking that by purchasing a PHEV, they are benefiting the environment and cutting money. Actually, PHEVs are only slightly improved than regular petrol and diesel cars in terms of fuel consumption, CO₂ production, and operating costs.”

Policy Discussion and Industry Lobbying

Plug-in hybrid vehicles have recently been drawn back into political discussions as automakers have pressed the EU to relax CO₂ targets. A planned prohibition on sales of new internal combustion vehicles in 2035 has faced intense lobbying from the automotive industry and resistance from EU countries with large automotive industries.

Several high-level politicians have suggested plug-in hybrids as a potential “flexibility” solution to introduce in the legislation.

An independent energy economics expert, who was unaffiliated with the study, called the report a “very useful contribution” after a long period in which parts of the automotive industry argued there was too little data to accurately assess real-world CO2 output.

“These findings show, without question, that the gap between lab and actual PHEV energy use and CO₂ output is much, much greater than for petrol or diesel vehicles,” the expert stated. “Any regulatory changes concerning PHEVs should be made with utmost caution and in the light of this evidence.”