🔗 Share this article

PHEVs emit almost five times more global warming emissions than lab-reported data indicate, as per a new analysis.

Widening Gap In Lab and Real-World Emissions

Data shows that PHEVs release just 19% less CO₂ than conventional gas and diesel vehicles, according to research conducted by a non-profit organization. That contrasts significantly with lab estimates, which assumed a 75% reduction in pollution.

Analysts studied data from onboard energy use meters of eight hundred thousand vehicles sold in the EU between 2021 and 2023. The team discovered that real-world CO₂ emissions from PHEVs in 2023 were nearly five times greater than official estimates, increased from 3.5 times in 2021.

“Real-world CO2 output are increasing, while official figures are falling,” said a senior researcher involved in the report. “That gap is growing and poses a significant issue. As a result, PHEVs pollute almost as much as gasoline cars.”

Primary Factors Driving the Emissions Gap

Researchers attributed most of the gap to overestimates of the “electric driving share” – the percentage of miles driven in battery power relative to overall mileage. The team found that just a quarter of travel was done in electric mode, while lab assumptions suggested 84%.

Additionally, when running in EV mode, emission levels were well above official projections. That occurred because electric motors were not strong sufficient to operate independently, resulting to combustion motors using fossil fuels for nearly a third of the distance covered in EV mode.

Policy and Financial Implications

According to estimates, the lowballing of PHEV emissions allowed four large carmaker companies to avoid more than €5bn in fines between 2021 and 2023, by falsely simplifying adherence with EU average fleet CO₂ standards.

Additionally, owners of PHEVs could pay about €500 extra per year in running expenses than would be estimated under laboratory conditions.

“The bold statements that manufacturers like to make about their PHEV cars are obviously way off the mark,” commented a transport analyst. “Buyers are being misled into believing that by purchasing a PHEV, they are benefiting the planet and cutting money. In reality, PHEVs are only slightly improved than regular petrol and diesel cars in terms of fuel use, CO₂ emissions, and running costs.”

Policy Debate and Automotive Lobbying

Plug-in hybrid vehicles have lately been brought again into policy discussions as automakers have lobbied the European Union to relax CO₂ targets. A proposed prohibition on new combustion engine vehicles in 2035 has faced intense lobbying from the car industry and opposition from EU countries with large automotive manufacturing.

Several senior politicians have proposed PHEVs as a potential “compromise” solution to include in the legislation.

An independent energy policy specialist, who was unaffiliated with the study, called the analysis a “highly valuable addition” after years in which parts of the car sector claimed there was too little data to properly assess real-world emissions.

“The results show, without question, that the gap between lab and actual PHEV energy use and CO₂ output is much, much greater than for petrol or conventional cars,” the expert stated. “Any policy adjustments regarding PHEVs should be made with utmost caution and considering this evidence.”