🔗 Share this article

PHEVs produce nearly five times more planet-heating pollution than lab-reported figures show, as per a new report.

Widening Discrepancy Between Official and Real-World Emissions

Statistics shows that PHEVs emit only 19% less CO₂ than traditional gas and diesel vehicles, based on analysis conducted by a non-profit group. This differs sharply with laboratory estimates, which suggested a 75% decrease in emissions.

Analysts studied data from in-vehicle energy use meters of eight hundred thousand vehicles registered in Europe from 2021 and 2023. The team found that actual CO₂ emissions from PHEVs in 2023 were nearly five times greater than official estimates, up from 3.5 times in 2021.

“Real-world CO2 output are increasing, while official figures are falling,” said a senior analyst involved in the report. “That discrepancy is widening and creates a significant problem. Consequently, PHEVs emit almost as much as gasoline cars.”

Primary Factors Driving the Discrepancy

Researchers attributed the majority of the difference to overestimates of the “utility factor” – the percentage of kilometers driven in electric power relative to overall distance. They determined that only 27% of driving was completed in EV mode, while official assumptions suggested over four-fifths.

Even, when running in EV mode, pollution amounts were significantly higher than official estimates. That occurred because EV motors were not strong enough to operate independently, resulting to combustion motors burning fossil fuels for almost one-third of the distance covered in electric mode.

Policy and Financial Consequences

According to calculations, the underestimation of PHEV CO2 output enabled four major automaker companies to escape more than €5bn in fines between 2021 and 2023, by falsely easing compliance with European Union average fleet CO₂ standards.

Additionally, owners of PHEVs could spend approximately €500 more annually in running costs than would be estimated under laboratory tests.

“The bold claims that automakers like to make about their PHEV vehicles are obviously far from the truth,” stated a transport expert. “Consumers 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 gas and diesel cars in terms of energy use, CO₂ production, and operating costs.”

Policy Debate and Industry Pressure

Plug-in hybrid vehicles have lately been brought again into policy debates as automakers have lobbied the EU to relax CO₂ standards. A planned prohibition on new combustion engine cars in 2035 has faced heavy pressure from the automotive sector and opposition from EU countries with significant automotive industries.

Some high-level politicians have suggested PHEVs as a potential “compromise” solution to include in the legislation.

An independent energy policy expert, who was unaffiliated with the study, called the analysis a “very useful contribution” after years in which segments of the car industry claimed there was too little information to accurately evaluate real-world emissions.

“The results demonstrate, without question, that the difference in official and real-world PHEV energy use and CO₂ output is much, much larger than for gasoline or diesel vehicles,” the expert said. “All regulatory changes concerning PHEVs should be implemented with extreme care and in the light of this evidence.”