🔗 Share this article

Plug-in hybrid electric vehicles produce nearly five times greater global warming pollution than official figures show, according to a recent analysis.

Growing Discrepancy In Official and Actual Emissions

Statistics shows that PHEVs release just 19% less CO₂ than conventional petrol and diesel vehicles, according to research carried out by a non-profit group. That differs sharply with lab estimates, which suggested a three-quarters reduction in pollution.

Analysts examined information from onboard fuel consumption meters of eight hundred thousand vehicles registered in the EU between 2021 and 2023. The team found that actual CO₂ output from PHEVs in 2023 were nearly five times greater than official estimates, increased from 3.5 times in 2021.

“Actual CO2 output are rising, while official figures are falling,” said a senior researcher involved in the report. “This gap is widening and poses a serious issue. Consequently, PHEVs emit almost as much as petrol vehicles.”

Primary Factors Behind the Discrepancy

Researchers linked the majority of the difference to overestimates of the “utility factor” – the percentage of miles driven in electric power compared to overall distance. They found that just 27% of travel was completed in EV mode, while lab estimates suggested over four-fifths.

Additionally, when running in electric mode, emission amounts were well above lab projections. That happened because EV motors were not strong enough to operate independently, resulting to combustion motors using gasoline for nearly one-third of the travel covered in EV mode.

Regulatory and Financial Consequences

According to estimates, the lowballing of PHEV emissions enabled several major carmaker groups to avoid over €5bn in fines between 2021 and 2023, by falsely simplifying compliance with European Union fleet-average CO₂ targets.

Furthermore, owners of PHEVs would pay about €500 extra per year in operating costs than would be estimated under laboratory conditions.

“The strong statements that automakers often promote about their plug-in hybrid cars are clearly far from the truth,” stated a transport analyst. “Buyers are being misled into believing that by purchasing a PHEV, they are helping the environment and saving money. Actually, PHEVs are little better than standard petrol and diesel cars in terms of energy consumption, CO₂ emissions, and running costs.”

Political Discussion and Industry Lobbying

Hybrid vehicles have lately been drawn again into political discussions as automakers have lobbied the European Union to weaken CO₂ standards. A proposed prohibition on new combustion engine vehicles in 2035 has faced intense lobbying from the automotive sector and resistance from member states with large car manufacturing.

Several high-level officials have proposed plug-in hybrids as a potential “compromise” solution to introduce in the regulation.

One external energy policy specialist, who was unaffiliated with the research, called the report a “highly valuable contribution” after years in which parts of the car industry argued there was too little data to properly evaluate real-world CO2 output.

“The results show, beyond any doubt, that the difference between official and real-world PHEV fuel consumption and CO₂ emissions is significantly larger than for petrol or conventional cars,” they stated. “All regulatory adjustments concerning PHEVs should be made with utmost care and in the light of this evidence.”