🔗 Share this article

PHEVs produce nearly five times greater global warming emissions than official figures indicate, according to a new analysis.

Growing Discrepancy Between Lab and Actual CO2 Output

Statistics shows that PHEVs release just 19% lower CO₂ than traditional gas and diesel vehicles, according to analysis carried out by a non-profit group. That contrasts significantly with laboratory estimates, which suggested a 75% decrease in pollution.

Analysts studied data from onboard fuel consumption monitors of 800,000 vehicles registered in the EU between 2021 and 2023. They found that real-world CO₂ output from PHEVs in 2023 were nearly five times higher than lab figures, up from three and a half times in 2021.

“Actual emissions are increasing, while official emissions are decreasing,” stated a lead analyst participating in the report. “That gap is growing and poses a serious issue. Consequently, PHEVs emit nearly as heavily as petrol cars.”

Primary Factors Behind the Emissions Gap

Analysts linked the majority of the gap to overestimates of the “electric driving share” – the ratio of miles driven in electric power relative to total mileage. They found that only 27% of travel was done in EV mode, whereas official estimates assumed 84%.

Additionally, when operating in electric mode, emission levels were significantly higher than lab projections. That happened because electric motors were not strong enough to function independently, leading to engines burning gasoline for nearly a third of the travel completed in electric mode.

Regulatory and Economic Implications

Based on calculations, the lowballing of PHEV emissions enabled four large carmaker groups to escape more than €5bn in penalties between 2021 and 2023, by artificially simplifying adherence with EU fleet-average CO₂ targets.

Furthermore, owners of PHEVs would spend approximately €500 more per year in operating costs than would be assumed under laboratory tests.

“The strong claims that automakers like to make about their PHEV vehicles are obviously way off the mark,” commented a transport expert. “Buyers are being misled into believing that by purchasing a PHEV, they are helping the environment and saving costs. In reality, PHEVs are only slightly improved than regular petrol and diesel vehicles in terms of fuel consumption, CO₂ emissions, and running expenses.”

Political Debate and Industry Lobbying

Hybrid vehicles have recently been drawn again into political discussions as automakers have pressed the European Union to weaken CO₂ standards. A proposed prohibition on new internal combustion vehicles in 2035 has faced heavy lobbying from the automotive industry and resistance from EU countries with large automotive manufacturing.

Several senior officials have suggested plug-in hybrids as a potential “flexibility” solution to introduce in the legislation.

One external energy policy specialist, who was not involved with the research, described the analysis a “highly valuable contribution” after years in which segments of the car industry argued there was too little information to properly evaluate real-world CO2 output.

“These findings demonstrate, without question, that the gap in lab and real-world PHEV fuel consumption and CO₂ emissions is much, much larger than for gasoline or conventional cars,” they stated. “All policy changes concerning PHEVs should be implemented with utmost caution and considering this data.”