🔗 Share this article

Plug-in hybrid cars produce nearly five times greater planet-heating pollution than lab-reported data indicate, as per a recent report.

Widening Gap In Official and Actual CO2 Output

Data reveals that PHEVs release only 19% lower CO₂ than conventional petrol and diesel vehicles, according to analysis carried out by a non-profit organization. That differs significantly with laboratory estimates, which suggested a three-quarters decrease in emissions.

Researchers examined information from onboard energy use meters of 800,000 cars registered in the EU between 2021 and 2023. The team discovered that real-world CO₂ emissions from PHEVs in 2023 were nearly five times greater than lab figures, increased from 3.5 times in 2021.

“Real-world CO2 output are rising, while lab-reported emissions are decreasing,” said a lead researcher participating in the study. “That gap is widening and poses a significant issue. As a result, PHEVs emit almost as much as gasoline cars.”

Key Reasons Behind the Discrepancy

Researchers attributed the majority of the gap to inflated estimates of the “utility factor” – the percentage of miles travelled in electric mode relative to total distance. The team determined that just a quarter of travel was completed in EV mode, whereas official assumptions suggested over four-fifths.

Additionally, when running in EV mode, emission levels were well above official estimates. This occurred because EV motors were not strong sufficient to operate alone, leading to engines using fossil fuels for nearly a third of the distance completed in EV mode.

Regulatory and Economic Implications

According to calculations, the underestimation of PHEV emissions enabled four large automaker groups to escape over €5bn in penalties from 2021 and 2023, by falsely simplifying adherence with European Union fleet-average CO₂ targets.

Furthermore, drivers of PHEVs would spend approximately €500 extra per year in running costs than would be estimated under lab tests.

“The strong claims that manufacturers often promote about their PHEV vehicles are clearly way off the mark,” stated a automotive expert. “Consumers are being misled into believing that by buying a PHEV, they are helping the environment and saving costs. In reality, PHEVs are only slightly better than standard gas and diesel vehicles in terms of energy use, CO₂ emissions, and running expenses.”

Political Discussion and Automotive Lobbying

Hybrid vehicles have recently been brought back into policy debates as carmakers have lobbied the European Union to weaken CO₂ targets. A planned ban on new combustion engine cars in 2035 has faced intense pressure from the automotive industry and resistance from EU countries with large automotive manufacturing.

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

One external energy economics expert, who was not involved with the study, described the analysis a “very useful addition” after a long period in which segments of the automotive sector claimed there was too little data to properly assess actual emissions.

“The results demonstrate, without question, that the difference in lab and actual PHEV energy use and CO₂ output is much, much larger than for petrol or conventional vehicles,” the expert stated. “Any policy adjustments concerning PHEVs should be implemented with extreme care and in the light of that data.”