🔗 Share this article

Plug-in hybrid electric vehicles produce almost five times more global warming pollution than lab-reported figures indicate, as per a new report.

Widening Gap Between Official and Actual CO2 Output

Statistics shows that PHEVs release only 19% less CO₂ than traditional petrol and diesel vehicles, according to research conducted by a advocacy organization. That differs significantly with laboratory estimates, which suggested a three-quarters reduction in emissions.

Researchers studied information from in-vehicle energy use monitors 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 figures, up from three and a half times in 2021.

“Real-world emissions are rising, while official figures are falling,” said a senior researcher involved in the report. “That gap is growing and poses a serious problem. As a result, PHEVs pollute nearly as much as petrol vehicles.”

Key Factors Driving the Discrepancy

Analysts linked the majority of the gap to overestimates of the “electric driving share” – the percentage of miles driven in electric mode relative to overall distance. They determined that just a quarter of driving was done in electric mode, while official assumptions assumed over four-fifths.

Additionally, when operating in EV mode, emission levels were significantly higher than lab projections. This happened because EV motors were not strong enough to operate independently, resulting to combustion motors using gasoline for nearly one-third of the distance completed in EV mode.

Regulatory and Financial Implications

According to calculations, the lowballing of PHEV emissions enabled four major carmaker companies to escape more than €5bn in fines from 2021 and 2023, by artificially easing compliance with EU average fleet CO₂ standards.

Furthermore, owners of PHEVs could pay about €500 more per year in operating costs than would be estimated under laboratory conditions.

“The strong claims that automakers like to make about their plug-in hybrid cars are obviously far from the mark,” commented a transport expert. “Buyers are being duped into believing that by buying a PHEV, they are helping the planet and saving costs. In reality, PHEVs are only slightly better than regular petrol and diesel cars in terms of fuel use, CO₂ production, and running expenses.”

Policy Debate and Industry Lobbying

Plug-in hybrid cars have lately been drawn again into political discussions as automakers have pressed the EU to relax CO₂ targets. A planned prohibition on sales of new combustion engine vehicles in 2035 has faced intense lobbying from the automotive industry and opposition from EU countries with large car manufacturing.

Some high-level politicians have proposed PHEVs as a possible “compromise” option to introduce in the regulation.

One external energy economics specialist, who was unaffiliated with the research, called the report a “highly valuable addition” after years in which segments of the automotive industry argued there was insufficient data to properly evaluate actual emissions.

“The results show, beyond any doubt, that the gap between lab and real-world PHEV energy use and CO₂ output is significantly larger than for petrol or diesel vehicles,” the expert stated. “All policy changes concerning PHEVs should be implemented with utmost care and considering that data.”