🔗 Share this article

Plug-in hybrid electric vehicles release nearly five times greater planet-heating pollution than lab-reported figures show, as per a new analysis.

Widening Discrepancy In Official and Actual Emissions

Statistics shows that PHEVs emit just 19% lower CO₂ than traditional gas and diesel cars, based on analysis conducted by a advocacy organization. That contrasts sharply with laboratory tests, which assumed a 75% decrease in emissions.

Researchers examined data from onboard energy use monitors of eight hundred thousand vehicles sold in Europe from 2021 and 2023. The team discovered that real-world CO₂ emissions from PHEVs in 2023 were nearly five times higher than lab estimates, up from three and a half times in 2021.

“Actual CO2 output are rising, while official figures are decreasing,” said a lead researcher involved in the report. “That gap is widening and poses a serious problem. As a result, PHEVs emit almost as heavily as gasoline vehicles.”

Key Reasons Driving the Discrepancy

Analysts linked the majority of the difference to inflated estimates of the “utility factor” – the percentage of miles travelled in electric power compared to overall mileage. They determined that just 27% of travel was done in EV mode, whereas official assumptions suggested 84%.

Even, when running in EV mode, pollution amounts were well above lab estimates. That occurred because EV motors were insufficiently powerful sufficient to operate independently, resulting to engines burning gasoline for almost a third of the distance completed in electric mode.

Policy and Financial Implications

Based on estimates, the underestimation of PHEV CO2 output allowed several major carmaker groups to avoid more than €5bn in fines between 2021 and 2023, by falsely simplifying compliance with EU average fleet CO₂ standards.

Furthermore, drivers of PHEVs could spend approximately €500 more per year in operating costs than would be estimated under laboratory tests.

“The bold claims that manufacturers like to make about their PHEV cars are clearly far from the mark,” commented a transport analyst. “Buyers are being duped into thinking that by purchasing a PHEV, they are benefiting the planet and saving costs. Actually, PHEVs are only slightly better than standard petrol and diesel vehicles in terms of energy use, CO₂ emissions, and running expenses.”

Policy Discussion and Automotive Pressure

Plug-in hybrid cars have lately been brought again into political debates as automakers have lobbied the EU to weaken CO₂ targets. A proposed prohibition on new internal combustion cars in 2035 has faced heavy pressure from the automotive industry and resistance from EU countries with significant automotive industries.

Some senior officials have suggested PHEVs as a potential “compromise” option to introduce in the legislation.

An external energy economics specialist, who was unaffiliated with the research, described the report a “very useful contribution” after a long period in which parts of the automotive sector argued there was too little information to properly assess actual CO2 output.

“The results demonstrate, without question, that the gap in official and real-world PHEV fuel consumption and CO₂ output is much, much greater than for petrol or conventional vehicles,” the expert stated. “All regulatory adjustments regarding PHEVs should be implemented with utmost caution and considering this data.”