🔗 Share this article

Plug-in hybrid electric vehicles emit nearly five times more planet-heating pollution than official data indicate, as per a new report.

Widening Discrepancy In Official and Real-World Emissions

Data reveals that PHEVs emit only one-fifth less CO₂ than conventional gas and diesel vehicles, according to analysis conducted by a advocacy group. This contrasts sharply with laboratory estimates, which assumed a three-quarters reduction in emissions.

Researchers studied data from in-vehicle energy use monitors of eight hundred thousand cars sold in the EU between 2021 and 2023. They found that real-world CO₂ output from PHEVs in 2023 were 4.9 times higher than official figures, up from three and a half times in 2021.

“Real-world CO2 output are rising, while lab-reported figures are falling,” stated a senior analyst involved in the study. “That discrepancy is widening and poses a serious problem. Consequently, PHEVs emit almost as much as gasoline cars.”

Primary Reasons Driving the Emissions Gap

Analysts linked the majority of the difference to overestimates of the “electric driving share” – the ratio of miles driven in battery power compared to total distance. The team found that only 27% of travel was completed in electric mode, whereas lab estimates suggested over four-fifths.

Even, when operating in electric mode, emission amounts were significantly higher than lab estimates. This happened because electric motors were insufficiently powerful sufficient to function independently, resulting to engines using fossil fuels for almost one-third of the travel completed in electric mode.

Regulatory and Financial Consequences

Based on estimates, the lowballing of PHEV CO2 output enabled four major carmaker companies to avoid more than €5bn in penalties from 2021 and 2023, by artificially simplifying compliance with European Union average fleet CO₂ targets.

Furthermore, owners of PHEVs could spend about €500 extra annually in operating expenses than would be assumed under lab tests.

“The strong statements that automakers like to make about their plug-in hybrid cars are clearly way off the truth,” commented a automotive expert. “Consumers are being duped into thinking that by purchasing a PHEV, they are helping the planet and saving money. Actually, PHEVs are little better than regular gas and diesel cars in terms of fuel use, CO₂ production, and operating expenses.”

Policy Discussion and Industry Pressure

Plug-in hybrid cars have recently been brought again into political discussions as automakers have pressed the European Union to relax CO₂ targets. A planned prohibition on sales of new combustion engine cars in 2035 has faced intense lobbying from the car sector and resistance from member states with significant car manufacturing.

Several senior politicians have proposed plug-in hybrids as a potential “flexibility” option to include in the regulation.

One independent energy economics expert, who was unaffiliated with the study, described the report a “highly valuable contribution” after a long period in which parts of the car industry argued there was insufficient data to properly evaluate real-world emissions.

“The results show, without question, that the gap between lab and actual PHEV fuel consumption and CO₂ emissions is significantly larger than for gasoline or diesel cars,” they stated. “All regulatory changes regarding PHEVs should be made with utmost care and considering that evidence.”