🔗 Share this article

Plug-in hybrid cars emit nearly five times greater planet-heating pollution than official data show, as per a new report.

Growing Discrepancy In Lab and Actual CO2 Output

Statistics reveals that PHEVs emit just 19% less CO₂ than traditional gas and diesel cars, according to research conducted by a advocacy organization. That differs sharply with laboratory estimates, which suggested a three-quarters decrease in emissions.

Analysts examined data from onboard energy use monitors of 800,000 cars sold in Europe between 2021 and 2023. The team discovered that actual CO₂ output from PHEVs in 2023 were nearly five times greater than official figures, increased from three and a half times in 2021.

“Actual CO2 output are rising, while official emissions are falling,” said a senior analyst involved in the study. “That gap is widening and poses a significant problem. As a result, PHEVs pollute nearly as much as petrol cars.”

Key Factors Behind the Emissions Gap

Analysts linked the majority of the gap to inflated estimates of the “utility factor” – the ratio of miles driven in battery power relative to total mileage. The team found that just 27% of driving was completed in EV mode, whereas lab assumptions assumed over four-fifths.

Additionally, when running in EV mode, pollution levels were significantly higher than official estimates. This happened because EV motors were not strong sufficient to function alone, leading to combustion motors using gasoline for nearly one-third of the travel completed in electric mode.

Regulatory and Financial Consequences

Based on calculations, the lowballing of PHEV emissions allowed several major carmaker groups to escape over €5bn in fines from 2021 and 2023, by artificially simplifying compliance with European Union average fleet CO₂ targets.

Additionally, owners of PHEVs could pay approximately €500 more per year in operating costs than would be estimated under lab tests.

“The strong statements that automakers like to make about their PHEV vehicles are clearly far from the truth,” commented a transport expert. “Consumers are being misled into thinking that by buying a PHEV, they are benefiting the planet and cutting money. In reality, PHEVs are little improved than regular petrol and diesel vehicles in terms of energy use, CO₂ production, and running expenses.”

Policy Debate and Industry Lobbying

Plug-in hybrid vehicles have recently been brought back into policy debates as automakers have pressed the European Union to weaken CO₂ standards. A planned prohibition on sales of new internal combustion cars in 2035 has faced intense pressure from the car industry and resistance from EU countries with significant car manufacturing.

Several senior politicians have suggested PHEVs as a potential “flexibility” option to introduce in the legislation.

One external energy policy expert, who was unaffiliated with the study, described the analysis a “very useful contribution” after years in which parts of the car industry claimed there was too little information to properly assess real-world CO2 output.

“These findings demonstrate, without question, that the difference in official and actual PHEV energy use and CO₂ emissions is significantly larger than for gasoline or conventional vehicles,” they said. “All regulatory adjustments concerning PHEVs should be implemented with utmost caution and in the light of this data.”