🔗 Share this article

Plug-in hybrid electric vehicles produce almost 5x more global warming pollution than official data indicate, as per a new analysis.

Growing Gap Between Official and Real-World CO2 Output

Statistics reveals that PHEVs emit only 19% less CO₂ than traditional gas and diesel cars, based on analysis conducted by a advocacy organization. This contrasts significantly with lab estimates, which assumed a three-quarters reduction in emissions.

Analysts examined data from onboard energy use meters of eight hundred thousand vehicles sold in Europe from 2021 and 2023. They discovered that real-world CO₂ emissions from PHEVs in 2023 were nearly five times higher than official estimates, up from 3.5 times in 2021.

“Real-world emissions are rising, while lab-reported figures are falling,” said a senior analyst participating in the report. “That discrepancy is widening and poses a significant problem. As a result, PHEVs pollute nearly as heavily as gasoline cars.”

Key Reasons Driving the Discrepancy

Researchers attributed the majority of the difference to inflated estimates of the “electric driving share” – the ratio of miles driven in electric mode relative to overall distance. They determined that only a quarter of driving was completed in electric mode, whereas lab assumptions assumed 84%.

Additionally, when operating in electric mode, emission levels were well above lab projections. This happened because EV motors were not strong sufficient to operate independently, resulting to engines using gasoline for nearly a third of the travel completed in electric mode.

Policy and Financial Implications

Based on estimates, the lowballing of PHEV emissions enabled several major carmaker companies to avoid over €5bn in penalties from 2021 and 2023, by falsely easing compliance with EU average fleet CO₂ targets.

Furthermore, owners of PHEVs could spend about €500 extra per year in running expenses than would be assumed under laboratory tests.

“The strong claims that manufacturers often promote about their PHEV cars are clearly far from the mark,” commented a transport analyst. “Consumers are being duped into believing that by purchasing a PHEV, they are helping the planet and cutting costs. In reality, PHEVs are little better than regular gas and diesel vehicles in terms of fuel use, CO₂ production, and operating expenses.”

Political Debate and Automotive Lobbying

Hybrid vehicles have lately been brought back into policy debates as carmakers have pressed the European Union to relax CO₂ targets. A planned ban on sales of new combustion engine cars in 2035 has faced heavy lobbying from the car sector and opposition from EU countries with large car industries.

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

One independent energy policy expert, who was not involved with the study, described the analysis a “highly valuable contribution” after years in which parts of the automotive industry claimed there was too little information to accurately assess real-world CO2 output.

“The results demonstrate, beyond any doubt, that the difference in official and real-world PHEV fuel consumption and CO₂ emissions is much, much greater than for gasoline or diesel vehicles,” they said. “All policy adjustments regarding PHEVs should be implemented with extreme care and considering that data.”