🔗 Share this article

PHEVs release nearly five times more planet-heating emissions than official data show, as per a new analysis.

Widening Discrepancy Between Official and Actual CO2 Output

Data shows that PHEVs release only 19% lower CO₂ than conventional gas and diesel vehicles, according to analysis conducted by a advocacy organization. This differs sharply with lab estimates, which assumed a three-quarters decrease in pollution.

Researchers examined data from in-vehicle fuel consumption monitors of eight hundred thousand vehicles registered in Europe between 2021 and 2023. The team discovered that real-world CO₂ output from PHEVs in 2023 were 4.9 times higher than lab figures, increased from 3.5 times in 2021.

“Actual CO2 output are rising, while official emissions are decreasing,” stated a senior analyst participating in the study. “This discrepancy is widening and creates a serious issue. As a result, PHEVs pollute nearly as much as petrol cars.”

Primary Reasons Driving the Emissions Gap

Analysts linked the majority of the difference to inflated estimates of the “utility factor” – the ratio of miles driven in electric power compared to total distance. They found that just 27% of travel was done in EV mode, while lab estimates assumed over four-fifths.

Additionally, when operating in EV mode, pollution amounts were well above lab estimates. This happened because EV motors were not strong enough to function alone, resulting to engines burning fossil fuels for nearly a third of the travel covered in EV mode.

Policy and Economic Implications

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

Furthermore, owners of PHEVs would spend approximately €500 extra annually in running expenses than is assumed under lab tests.

“The bold statements that automakers often promote about their PHEV vehicles are obviously far from the mark,” commented a transport analyst. “Buyers are being misled into thinking that by buying a PHEV, they are benefiting the environment and saving costs. Actually, PHEVs are little better than standard gas and diesel cars in terms of fuel consumption, CO₂ production, and running expenses.”

Political Debate and Industry Lobbying

Plug-in hybrid cars have recently been drawn again into political debates as automakers have lobbied the European Union to relax CO₂ targets. A proposed ban on sales of new internal combustion cars in 2035 has faced heavy pressure from the automotive sector and resistance from EU countries with large car manufacturing.

Several high-level officials have proposed plug-in hybrids as a potential “flexibility” option to include in the regulation.

One external energy economics expert, who was not involved with the study, called the analysis a “highly valuable addition” after a long period in which segments of the automotive industry claimed there was insufficient information to properly evaluate actual emissions.

“These findings demonstrate, without question, that the gap in official and actual PHEV fuel consumption and CO₂ emissions is significantly greater than for petrol or conventional cars,” the expert stated. “All regulatory changes regarding PHEVs should be made with extreme care and considering that evidence.”