🔗 Share this article

PHEVs produce nearly five times more global warming pollution than official figures show, according to a new report.

Growing Discrepancy In Lab and Real-World Emissions

Data shows that PHEVs emit only 19% less CO₂ than conventional gas and diesel vehicles, based on research conducted by a non-profit organization. That differs significantly with laboratory tests, which assumed a three-quarters reduction in pollution.

Researchers studied data from onboard fuel consumption monitors of 800,000 vehicles registered in Europe from 2021 and 2023. They found that real-world CO₂ output from PHEVs in 2023 were nearly five times greater than lab figures, up from three and a half times in 2021.

“Real-world CO2 output are rising, while lab-reported figures are falling,” said a lead researcher involved in the study. “That discrepancy is growing and creates a serious problem. As a result, PHEVs emit almost as heavily as gasoline cars.”

Primary Reasons Behind the Emissions Gap

Analysts attributed the majority of the gap to inflated estimates of the “utility factor” – the ratio of kilometers travelled in battery power relative to total mileage. They found that just a quarter of travel was done in electric mode, while lab assumptions suggested over four-fifths.

Even, when running in electric mode, pollution amounts were significantly higher than lab estimates. That happened because electric motors were insufficiently powerful enough to operate independently, leading to engines using fossil fuels for nearly one-third of the travel completed in electric mode.

Policy and Financial Implications

According to calculations, the lowballing of PHEV CO2 output enabled several major carmaker companies to escape more than €5bn in penalties between 2021 and 2023, by falsely easing compliance with EU average fleet CO₂ targets.

Furthermore, drivers of PHEVs would spend approximately €500 more annually in operating expenses than is assumed under lab tests.

“The bold statements that automakers often promote about their PHEV cars are clearly far from the mark,” commented a transport expert. “Buyers are being misled into thinking that by purchasing a PHEV, they are benefiting the planet and cutting money. In reality, PHEVs are only slightly better than standard petrol and diesel cars in terms of fuel consumption, CO₂ production, and operating expenses.”

Policy Debate and Industry Pressure

Hybrid cars have lately been drawn back into policy debates as carmakers have pressed the European Union to relax CO₂ standards. A proposed ban on sales of new internal combustion vehicles in 2035 has faced heavy pressure from the car industry and opposition from EU countries with large automotive manufacturing.

Several senior politicians have proposed PHEVs as a possible “flexibility” option to include in the legislation.

One external energy policy expert, who was not involved with the research, described the analysis a “highly valuable contribution” after years in which segments of the automotive sector argued there was too little information to accurately evaluate actual emissions.

“These findings demonstrate, beyond any doubt, that the difference in official and real-world PHEV fuel consumption and CO₂ emissions is much, much greater than for petrol or conventional vehicles,” the expert stated. “Any regulatory changes regarding PHEVs should be made with extreme caution and considering this evidence.”