🔗 Share this article

PHEVs produce almost 5x more global warming pollution than lab-reported figures indicate, as per a recent analysis.

Widening Gap Between Lab and Actual CO2 Output

Statistics reveals that PHEVs emit only 19% less CO₂ than conventional petrol and diesel vehicles, according to research carried out by a advocacy group. That contrasts significantly with lab estimates, which suggested a three-quarters decrease in pollution.

Analysts examined data from in-vehicle energy use monitors of 800,000 vehicles sold in the EU from 2021 and 2023. The team found that actual CO₂ emissions from PHEVs in 2023 were nearly five times greater than official figures, up from 3.5 times in 2021.

“Actual emissions are increasing, while official emissions are decreasing,” said a senior analyst participating in the report. “This gap is growing and creates a serious issue. Consequently, PHEVs emit almost as heavily as gasoline cars.”

Primary Reasons Driving the Emissions Gap

Analysts attributed the majority of the difference to overestimates of the “electric driving share” – the percentage of miles driven in battery mode relative to total distance. The team determined that just 27% of travel was completed in EV mode, while official estimates assumed 84%.

Additionally, when operating in EV mode, emission levels were significantly higher than lab estimates. This happened because EV motors were insufficiently powerful enough to operate independently, leading to engines using fossil fuels for nearly one-third of the distance covered in electric mode.

Policy and Economic Implications

Based on calculations, the underestimation of PHEV CO2 output allowed several large automaker groups to avoid more than €5bn in penalties from 2021 and 2023, by falsely simplifying compliance with European Union average fleet CO₂ targets.

Furthermore, drivers of PHEVs would spend approximately €500 extra annually in operating costs than would be assumed under lab conditions.

“The bold claims that manufacturers like to make about their plug-in hybrid cars are obviously way off the mark,” stated a transport analyst. “Consumers are being duped into believing that by buying a PHEV, they are benefiting the planet and saving money. Actually, PHEVs are little better than regular petrol and diesel cars in terms of fuel consumption, CO₂ production, and operating expenses.”

Political Discussion and Automotive Pressure

Hybrid cars have recently been brought again into political discussions as automakers have lobbied the EU to relax CO₂ standards. A proposed prohibition on new internal combustion cars in 2035 has faced intense lobbying from the car sector and opposition from EU countries with significant automotive manufacturing.

Several senior politicians have suggested PHEVs as a potential “flexibility” option to introduce in the regulation.

One external energy policy specialist, who was unaffiliated with the research, called the analysis a “very useful contribution” after a long period in which segments of the automotive industry claimed there was too little data to properly evaluate actual emissions.

“These findings demonstrate, without question, that the gap between lab and actual PHEV energy use and CO₂ output is significantly greater than for petrol or conventional cars,” they said. “Any regulatory adjustments regarding PHEVs should be implemented with extreme care and in the light of that evidence.”