🔗 Share this article

Plug-in hybrid cars emit almost 5x greater global warming emissions than lab-reported data indicate, as per a recent report.

Widening Gap Between Lab and Real-World Emissions

Statistics shows that PHEVs emit only 19% lower CO₂ than conventional petrol and diesel vehicles, according to research carried out by a non-profit group. This differs significantly with lab estimates, which suggested a 75% decrease in pollution.

Researchers studied information from in-vehicle fuel consumption monitors of eight hundred thousand vehicles registered in the EU from 2021 and 2023. They found that real-world CO₂ emissions from PHEVs in 2023 were 4.9 times higher than official figures, increased from three and a half times in 2021.

“Actual emissions are rising, while official figures are falling,” stated a lead researcher involved in the study. “That discrepancy is growing and poses a significant problem. As a result, PHEVs pollute almost as heavily as petrol vehicles.”

Key Reasons Driving the Emissions Gap

Researchers attributed most of the difference to overestimates of the “electric driving share” – the percentage of miles driven in electric power compared to total distance. The team found that only a quarter of driving was done in electric mode, while lab assumptions suggested 84%.

Even, when running in EV mode, emission amounts were significantly higher than official projections. That occurred because EV motors were insufficiently powerful sufficient to function independently, resulting to engines burning fossil fuels for almost one-third of the distance covered in electric mode.

Policy and Financial Implications

Based on calculations, the underestimation of PHEV CO2 output allowed several large carmaker groups to avoid over €5bn in fines between 2021 and 2023, by artificially easing compliance with European Union average fleet CO₂ targets.

Additionally, drivers of PHEVs could spend approximately €500 more per year in running expenses than would be estimated under lab tests.

“The bold claims that manufacturers often promote about their plug-in hybrid cars are obviously way off the mark,” commented a transport analyst. “Consumers are being duped into thinking that by buying a PHEV, they are helping the environment and cutting money. Actually, PHEVs are little better than standard gas and diesel vehicles in terms of energy consumption, CO₂ production, and running expenses.”

Policy Discussion and Industry Pressure

Plug-in hybrid vehicles have lately been drawn again into political debates as carmakers have pressed the European Union to relax CO₂ targets. A planned prohibition on new internal combustion vehicles in 2035 has faced heavy lobbying from the car industry and resistance from member states with significant automotive manufacturing.

Some high-level officials have proposed plug-in hybrids as a possible “flexibility” option to introduce in the legislation.

An independent energy policy expert, who was unaffiliated with the study, called the report a “very useful addition” after a long period in which segments of the automotive industry argued there was too little data to accurately evaluate real-world CO2 output.

“These findings show, beyond any doubt, that the gap in official and real-world PHEV fuel consumption and CO₂ emissions is much, much greater than for gasoline or conventional cars,” they said. “Any policy adjustments regarding PHEVs should be made with extreme caution and considering this evidence.”