🔗 Share this article

Plug-in hybrid electric vehicles release nearly five times more global warming pollution than official data indicate, as per a recent report.

Growing Discrepancy Between Official and Real-World Emissions

Data shows that PHEVs release only one-fifth lower CO₂ than conventional petrol and diesel cars, based on research carried out by a non-profit group. This contrasts significantly with laboratory estimates, which suggested a 75% decrease in pollution.

Analysts examined data from in-vehicle energy use monitors of 800,000 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 lab estimates, increased from 3.5 times in 2021.

“Actual emissions are increasing, while official figures are falling,” said a senior analyst involved in the report. “This discrepancy is widening and poses a significant problem. As a result, PHEVs emit almost as heavily as petrol vehicles.”

Primary Reasons Driving the Emissions Gap

Analysts linked most of the gap to inflated estimates of the “utility factor” – the percentage of miles driven in electric mode compared to total distance. The team determined that just a quarter of driving was done in electric mode, while official estimates assumed over four-fifths.

Even, when operating in EV mode, pollution amounts were well above lab estimates. This occurred because electric motors were insufficiently powerful enough to function alone, leading to engines burning gasoline for nearly one-third of the travel covered in electric mode.

Regulatory and Financial Consequences

According to estimates, the lowballing of PHEV CO2 output enabled several large automaker companies to escape more than €5bn in penalties between 2021 and 2023, by falsely simplifying adherence with European Union fleet-average CO₂ targets.

Additionally, drivers of PHEVs could pay approximately €500 extra per year in operating costs than is estimated under laboratory tests.

“The bold claims that manufacturers often promote about their plug-in hybrid cars are clearly far from the mark,” stated a transport expert. “Consumers are being duped into believing that by purchasing a PHEV, they are benefiting the planet and cutting costs. Actually, PHEVs are little improved than standard gas and diesel cars in terms of energy use, CO₂ emissions, and running costs.”

Political Debate and Automotive Lobbying

Plug-in hybrid cars have recently been drawn back into policy debates as automakers have lobbied the EU to weaken CO₂ standards. A proposed prohibition on sales of new internal combustion cars in 2035 has faced intense pressure from the automotive industry and resistance from EU countries with significant automotive industries.

Several high-level politicians have proposed PHEVs as a potential “flexibility” option to include in the legislation.

An external energy policy expert, who was unaffiliated with the research, called the analysis a “highly valuable addition” after years in which parts of the automotive sector argued there was insufficient data to properly evaluate real-world emissions.

“These findings demonstrate, beyond any doubt, that the gap in official and actual PHEV energy use and CO₂ emissions is much, much greater than for petrol or conventional cars,” the expert stated. “All regulatory changes concerning PHEVs should be implemented with extreme care and in the light of that evidence.”