🔗 Share this article

Plug-in hybrid cars release nearly 5x greater planet-heating emissions than lab-reported data show, as per a new analysis.

Growing Gap Between Official and Actual Emissions

Data shows that PHEVs emit just one-fifth less CO₂ than traditional petrol and diesel vehicles, according to analysis conducted by a non-profit organization. This differs significantly with laboratory estimates, which suggested a 75% decrease in emissions.

Researchers examined information from in-vehicle energy use monitors of eight hundred thousand cars registered in Europe from 2021 and 2023. They found that actual CO₂ emissions from PHEVs in 2023 were 4.9 times higher than official estimates, up from three and a half times in 2021.

“Actual CO2 output are rising, while official figures are falling,” stated a senior analyst involved in the study. “That discrepancy is widening and poses a serious issue. Consequently, PHEVs pollute nearly as heavily as petrol cars.”

Key Factors Behind the Discrepancy

Analysts linked the majority of the gap to overestimates of the “utility factor” – the percentage of kilometers driven in electric power relative to total distance. The team found that just 27% of driving was completed in EV mode, whereas lab estimates assumed 84%.

Even, when operating in EV mode, pollution levels were well above lab projections. This occurred because EV motors were not strong enough to operate alone, leading to combustion motors burning fossil fuels for almost one-third of the travel completed in EV mode.

Policy and Economic Implications

Based on estimates, the lowballing of PHEV emissions enabled several large automaker companies to escape more than €5bn in penalties between 2021 and 2023, by artificially simplifying adherence with European Union average fleet CO₂ targets.

Additionally, owners of PHEVs could pay approximately €500 extra annually in operating expenses than would be assumed under lab tests.

“The bold statements that manufacturers often promote about their plug-in hybrid vehicles are clearly far from the mark,” stated a transport analyst. “Buyers are being duped into thinking that by purchasing a PHEV, they are helping the environment and saving money. Actually, PHEVs are only slightly better than standard gas and diesel cars in terms of fuel use, CO₂ production, and running expenses.”

Political Discussion and Automotive Lobbying

Plug-in hybrid vehicles have lately been brought back into political discussions as carmakers have lobbied the EU to relax CO₂ targets. A proposed ban on new internal combustion vehicles in 2035 has faced heavy lobbying from the car industry and resistance from member states with significant car industries.

Several high-level officials have proposed PHEVs as a potential “compromise” solution to include in the regulation.

An independent energy economics specialist, who was unaffiliated with the study, called the report a “very useful contribution” after years in which segments of the automotive sector claimed there was too little data to accurately assess actual CO2 output.

“These findings demonstrate, beyond any doubt, that the gap between lab and actual PHEV energy use and CO₂ output is significantly greater than for petrol or conventional vehicles,” the expert stated. “All regulatory adjustments concerning PHEVs should be implemented with utmost caution and considering this evidence.”