🔗 Share this article

Plug-in hybrid electric vehicles emit almost five times more global warming pollution than lab-reported data indicate, as per a new analysis.

Growing Discrepancy Between Official and Actual CO2 Output

Data shows that PHEVs release just 19% less CO₂ than conventional petrol and diesel vehicles, based on research carried out by a advocacy organization. This contrasts significantly with lab estimates, which assumed a three-quarters reduction in emissions.

Researchers examined data from onboard fuel consumption meters of 800,000 vehicles sold in Europe between 2021 and 2023. They found that real-world CO₂ output from PHEVs in 2023 were 4.9 times greater than lab estimates, increased from three and a half times in 2021.

“Actual CO2 output are rising, while lab-reported emissions are falling,” stated a senior analyst participating in the study. “That discrepancy is widening and poses a serious issue. Consequently, PHEVs emit almost as much as petrol vehicles.”

Key Factors Driving the Emissions Gap

Analysts linked the majority of the difference to overestimates of the “electric driving share” – the ratio of kilometers driven in battery mode relative to total mileage. They found that just a quarter of driving was done in electric mode, while lab assumptions suggested over four-fifths.

Even, when operating in electric mode, emission amounts were significantly higher than official projections. That occurred because EV motors were not strong enough to operate independently, leading to engines using fossil fuels for almost one-third of the distance covered in EV mode.

Policy and Financial Implications

Based on estimates, the lowballing of PHEV emissions enabled several major automaker groups to escape over €5bn in fines between 2021 and 2023, by falsely easing adherence with EU average fleet CO₂ standards.

Additionally, owners of PHEVs would spend approximately €500 more annually in running costs than is estimated under laboratory conditions.

“The strong claims that automakers like to make about their PHEV vehicles are obviously way off the mark,” commented a transport expert. “Buyers are being duped into thinking that by buying a PHEV, they are benefiting the environment and saving costs. In reality, PHEVs are only slightly improved than regular gas and diesel cars in terms of fuel use, CO₂ production, and running expenses.”

Political Debate and Industry Lobbying

Plug-in hybrid cars have lately been brought back into policy debates as carmakers have pressed the EU to relax CO₂ standards. A planned ban on sales of new internal combustion cars in 2035 has faced intense pressure from the automotive sector and opposition from EU countries with large automotive industries.

Some senior officials have proposed plug-in hybrids as a potential “flexibility” option to include in the legislation.

One external energy policy specialist, who was unaffiliated with the study, described the report a “very useful contribution” after years in which segments of the automotive sector argued there was insufficient data to properly evaluate actual emissions.

“The results show, without question, that the gap in official and real-world PHEV fuel consumption and CO₂ emissions is much, much greater than for gasoline or diesel vehicles,” they stated. “All regulatory adjustments regarding PHEVs should be implemented with utmost caution and in the light of that data.”