🔗 Share this article

Plug-in hybrid cars release almost 5x more planet-heating pollution than lab-reported figures show, according to a new analysis.

Growing Discrepancy Between Lab and Real-World CO2 Output

Statistics reveals that PHEVs emit just one-fifth lower CO₂ than traditional petrol and diesel vehicles, based on research conducted by a advocacy organization. That differs significantly with laboratory estimates, which suggested a three-quarters reduction in pollution.

Analysts examined data from onboard energy use meters of 800,000 vehicles registered in Europe between 2021 and 2023. The team found that real-world CO₂ emissions from PHEVs in 2023 were nearly five times greater than official figures, increased from three and a half times in 2021.

“Actual emissions are rising, while official figures are falling,” said a lead analyst participating in the study. “This discrepancy is growing and creates a significant problem. As a result, PHEVs emit nearly as much as petrol vehicles.”

Primary Reasons Behind the Emissions Gap

Analysts attributed the majority of the difference to overestimates of the “utility factor” – the ratio of kilometers travelled in electric mode relative to overall mileage. The team found that only 27% of travel was completed in electric mode, while official assumptions suggested over four-fifths.

Even, when running in EV mode, emission levels were well above official estimates. This occurred because electric motors were insufficiently powerful sufficient to function independently, resulting to engines burning gasoline for almost one-third of the distance completed in EV mode.

Policy and Economic Implications

Based on estimates, the lowballing of PHEV emissions enabled four major automaker groups to avoid more than €5bn in penalties between 2021 and 2023, by falsely simplifying compliance with European Union average fleet CO₂ standards.

Furthermore, owners of PHEVs could pay approximately €500 more annually in operating expenses than is estimated under laboratory conditions.

“The bold claims that automakers often promote about their plug-in hybrid vehicles are clearly way off the mark,” stated a transport expert. “Consumers are being duped into believing that by purchasing a PHEV, they are helping the planet and cutting money. In reality, PHEVs are little better than standard petrol and diesel cars in terms of fuel consumption, CO₂ production, and running expenses.”

Political Discussion and Industry Lobbying

Hybrid vehicles have lately been brought again into political discussions as carmakers have lobbied the European Union to weaken CO₂ targets. A proposed prohibition on new combustion engine cars in 2035 has faced intense pressure from the car sector and resistance from member states with significant car manufacturing.

Several high-level officials have proposed plug-in hybrids as a potential “compromise” solution to introduce in the regulation.

One external energy policy expert, who was not involved with the study, called the analysis a “very useful addition” after a long period in which segments of the automotive industry argued there was insufficient data to properly evaluate actual emissions.

“The results show, beyond any doubt, that the gap between official and actual PHEV energy use and CO₂ emissions is much, much greater than for gasoline or diesel vehicles,” the expert stated. “Any regulatory changes concerning PHEVs should be made with extreme caution and considering that evidence.”