🔗 Share this article

Plug-in hybrid electric vehicles produce nearly 5x more global warming emissions than official data show, as per a new report.

Growing Gap In Lab and Actual Emissions

Statistics reveals that PHEVs emit just one-fifth less CO₂ than traditional gas and diesel vehicles, based on analysis conducted by a non-profit organization. That contrasts sharply with lab estimates, which suggested a three-quarters decrease in emissions.

Researchers studied data from in-vehicle fuel consumption monitors of eight hundred thousand vehicles sold in Europe from 2021 and 2023. The team discovered that real-world CO₂ emissions from PHEVs in 2023 were 4.9 times higher than lab figures, increased from 3.5 times in 2021.

“Actual emissions are rising, while lab-reported figures are decreasing,” stated a lead researcher involved in the report. “That gap is widening and creates a significant problem. Consequently, PHEVs pollute almost as heavily as petrol vehicles.”

Key Factors Driving the Emissions Gap

Analysts attributed the majority of the gap to overestimates of the “electric driving share” – the ratio of kilometers travelled in battery power relative to total mileage. The team found that only 27% of driving was completed in EV mode, while official assumptions suggested over four-fifths.

Additionally, when running in electric mode, pollution levels were significantly higher than official estimates. This happened because electric motors were insufficiently powerful enough to function independently, resulting to combustion motors burning fossil fuels for almost one-third of the travel completed in EV mode.

Policy and Economic Consequences

Based on calculations, the underestimation of PHEV emissions allowed four major automaker groups to avoid over €5bn in penalties from 2021 and 2023, by falsely simplifying compliance with EU average fleet CO₂ standards.

Additionally, owners of PHEVs could pay about €500 more annually in running expenses than is estimated under lab tests.

“The strong claims that manufacturers like to make about their PHEV vehicles are obviously way off the mark,” commented a automotive expert. “Buyers are being misled into believing that by purchasing a PHEV, they are helping the environment and saving costs. Actually, PHEVs are only slightly better than regular petrol and diesel cars in terms of fuel consumption, CO₂ production, and operating expenses.”

Policy Discussion and Industry Pressure

Hybrid vehicles have lately been drawn back into political discussions as carmakers have pressed the European Union to relax CO₂ standards. A planned ban on sales of new combustion engine cars in 2035 has faced intense lobbying from the automotive sector and resistance from member states with large car manufacturing.

Some senior politicians have proposed plug-in hybrids as a possible “flexibility” solution to introduce in the regulation.

One independent energy economics expert, who was not involved with the study, called the analysis a “very useful contribution” after a long period in which segments of the automotive sector claimed there was too little data to properly assess actual emissions.

“The results demonstrate, beyond any doubt, that the gap between lab and real-world PHEV energy use and CO₂ output is significantly greater than for petrol or diesel vehicles,” they said. “All policy adjustments regarding PHEVs should be implemented with extreme caution and considering that evidence.”