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PHEVs release nearly 5x more global warming pollution than lab-reported data indicate, as per a recent report.

Growing Gap Between Official and Real-World Emissions

Statistics shows that PHEVs emit just one-fifth lower CO₂ than conventional gas and diesel vehicles, according to research carried out by a non-profit group. This contrasts significantly with lab tests, which assumed a 75% decrease in pollution.

Analysts studied data from onboard energy use meters of eight hundred thousand vehicles sold in the EU between 2021 and 2023. They found that actual CO₂ emissions from PHEVs in 2023 were 4.9 times higher than lab figures, up from 3.5 times in 2021.

“Real-world CO2 output are increasing, while lab-reported emissions are falling,” said a senior analyst participating in the report. “This discrepancy is widening and creates a significant issue. As a result, PHEVs pollute almost as much as petrol cars.”

Key Factors Driving the Discrepancy

Researchers linked most of the difference to inflated estimates of the “utility factor” – the ratio of miles driven in battery power compared to overall distance. They found that just 27% of travel was completed in electric mode, while lab assumptions assumed 84%.

Even, when running in electric mode, emission amounts were significantly higher than lab estimates. That occurred because EV motors were insufficiently powerful sufficient to function alone, resulting to combustion motors using gasoline for nearly a third of the travel covered in EV mode.

Regulatory and Economic Consequences

Based on estimates, the underestimation of PHEV CO2 output enabled several major carmaker companies to avoid more than €5bn in penalties between 2021 and 2023, by falsely simplifying adherence with EU fleet-average CO₂ standards.

Additionally, owners of PHEVs would pay about €500 extra per year in running expenses than would be estimated under lab conditions.

“The strong claims that manufacturers often promote about their plug-in hybrid vehicles are clearly way off the truth,” stated a transport analyst. “Consumers are being duped into thinking that by purchasing a PHEV, they are helping the planet and saving costs. In reality, PHEVs are only slightly better than standard petrol and diesel vehicles in terms of energy consumption, CO₂ production, and operating expenses.”

Political Discussion and Industry Lobbying

Plug-in hybrid vehicles have lately been brought again into political debates as automakers have pressed the European Union to relax CO₂ standards. A proposed ban on new combustion engine vehicles in 2035 has faced heavy pressure from the automotive sector and resistance from EU countries with significant car industries.

Some senior politicians have suggested plug-in hybrids as a potential “compromise” option to include in the legislation.

An external energy economics specialist, who was not involved with the research, called the report a “very useful addition” after years in which parts of the car sector argued there was insufficient data to accurately evaluate real-world CO2 output.

“The results show, without question, that the difference in official and real-world PHEV energy use and CO₂ emissions is much, much greater than for gasoline or conventional cars,” the expert stated. “All policy adjustments regarding PHEVs should be made with utmost caution and considering this evidence.”