🔗 Share this article

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

Widening Discrepancy In Official and Actual CO2 Output

Data reveals that PHEVs release just one-fifth lower CO₂ than traditional gas and diesel cars, according to analysis conducted by a non-profit organization. That contrasts sharply with lab tests, which assumed a 75% reduction in pollution.

Researchers examined data from onboard fuel consumption meters of eight hundred thousand vehicles registered in the EU from 2021 and 2023. They discovered that real-world CO₂ output from PHEVs in 2023 were nearly five times higher than official figures, increased from three and a half times in 2021.

“Real-world CO2 output are rising, while lab-reported figures are falling,” stated a senior analyst participating in the study. “That gap is growing and creates a significant issue. As a result, PHEVs pollute nearly as much as gasoline vehicles.”

Key Reasons Driving the Discrepancy

Analysts linked most of the gap to inflated estimates of the “utility factor” – the percentage of miles travelled in battery power compared to overall distance. The team determined that just a quarter of travel was completed in EV mode, whereas official assumptions suggested 84%.

Even, when running in electric mode, emission levels were significantly higher than official estimates. This occurred because EV motors were insufficiently powerful enough to operate independently, leading to combustion motors using gasoline for nearly a third of the travel covered in electric mode.

Regulatory and Financial Consequences

According to calculations, the underestimation of PHEV CO2 output enabled several large carmaker companies to avoid more than €5bn in penalties from 2021 and 2023, by falsely easing adherence with European Union average fleet CO₂ standards.

Additionally, owners of PHEVs would spend approximately €500 extra annually in running costs than would be assumed under lab conditions.

“The strong statements that automakers often promote about their PHEV vehicles are obviously far from the mark,” commented a automotive expert. “Buyers are being misled into thinking that by buying a PHEV, they are helping the planet and cutting costs. In reality, PHEVs are little improved than regular petrol and diesel vehicles in terms of energy use, CO₂ production, and operating expenses.”

Policy Debate and Industry Lobbying

Plug-in hybrid cars have recently been brought back into political debates as carmakers have pressed the EU to weaken CO₂ standards. A proposed prohibition on new combustion engine cars in 2035 has faced intense pressure from the automotive sector and opposition from EU countries with significant automotive industries.

Some high-level officials have suggested PHEVs as a possible “flexibility” option to introduce in the legislation.

An external energy policy specialist, who was unaffiliated with the research, called the report a “very useful addition” after years in which parts of the automotive sector claimed there was insufficient information to accurately assess real-world CO2 output.

“These findings show, beyond any doubt, that the difference in official and actual PHEV energy use and CO₂ emissions is significantly larger than for petrol or diesel vehicles,” the expert said. “Any policy changes regarding PHEVs should be made with extreme care and in the light of this evidence.”