🔗 Share this article

Plug-in hybrid electric vehicles produce almost 5x more planet-heating pollution than lab-reported data show, according to a recent analysis.

Widening Gap In Official and Real-World CO2 Output

Statistics shows that PHEVs emit only 19% less CO₂ than traditional petrol and diesel cars, based on analysis carried out by a advocacy group. This differs significantly with laboratory estimates, which assumed a three-quarters decrease in pollution.

Researchers studied information from in-vehicle fuel consumption monitors of eight hundred thousand cars registered in Europe from 2021 and 2023. The team discovered that real-world CO₂ emissions from PHEVs in 2023 were 4.9 times greater than official estimates, up from three and a half times in 2021.

“Actual emissions are rising, while official figures are falling,” stated a lead analyst participating in the report. “This discrepancy is widening and creates a significant issue. Consequently, PHEVs emit almost as much as petrol vehicles.”

Key Reasons Driving the Emissions Gap

Analysts linked the majority of the difference to inflated estimates of the “electric driving share” – the ratio of miles travelled in electric mode compared to total distance. The team found that just a quarter of travel was done in EV mode, while official estimates suggested over four-fifths.

Even, when running in EV mode, emission levels were significantly higher than official estimates. This occurred because EV motors were insufficiently powerful enough to operate alone, leading to engines using fossil fuels for almost a third of the travel completed in electric mode.

Regulatory and Economic Consequences

Based on calculations, the lowballing of PHEV CO2 output allowed four major carmaker groups to escape more than €5bn in penalties from 2021 and 2023, by falsely easing compliance with EU average fleet CO₂ targets.

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

“The bold claims that manufacturers often promote about their PHEV cars are clearly way off the truth,” stated a transport analyst. “Consumers are being misled into believing that by buying a PHEV, they are benefiting the planet and cutting costs. In reality, PHEVs are only slightly better than standard petrol and diesel cars in terms of energy use, CO₂ emissions, and operating expenses.”

Policy Debate and Automotive Lobbying

Hybrid cars have lately been brought again into political discussions as carmakers have lobbied the EU to weaken CO₂ targets. A planned prohibition on new internal combustion vehicles in 2035 has faced intense lobbying from the automotive industry and opposition from EU countries with significant automotive manufacturing.

Several senior officials have suggested plug-in hybrids as a potential “compromise” option to introduce in the regulation.

An external energy policy specialist, who was not involved with the study, called the report a “highly valuable contribution” after a long period in which parts of the car sector claimed there was insufficient data to accurately assess actual CO2 output.

“The results show, beyond any doubt, that the gap in lab and real-world PHEV energy use and CO₂ output is significantly larger than for petrol or conventional cars,” the expert stated. “All policy changes concerning PHEVs should be implemented with extreme care and considering this evidence.”