Plug in Hybrid electric Cars Pollute Almost as Heavily as Gasoline Cars, Study Reveals

Plug-in hybrid electric vehicles emit nearly 5x more planet-heating pollution than lab-reported figures indicate, as per a new analysis.

Growing Gap In Official and Real-World Emissions

Data reveals that PHEVs emit only 19% less CO₂ than traditional gas and diesel vehicles, according to research carried out by a non-profit organization. This contrasts sharply with lab estimates, which assumed a 75% decrease in pollution.

Researchers studied information from onboard fuel consumption meters of 800,000 cars registered in the EU from 2021 and 2023. The team discovered that real-world CO₂ emissions from PHEVs in 2023 were nearly five times higher than lab figures, up from three and a half times in 2021.

“Actual emissions are rising, while official figures are falling,” said a senior analyst involved in the study. “This gap is widening and poses a significant issue. As a result, PHEVs emit nearly as much as petrol vehicles.”

Primary Factors Driving the Emissions Gap

Researchers linked most of the gap to inflated estimates of the “electric driving share” – the ratio of kilometers travelled in battery power compared to overall mileage. The team determined that just a quarter of driving was completed in electric mode, while lab assumptions suggested over four-fifths.

Even, when running in EV mode, emission amounts were significantly higher than lab projections. That occurred because electric motors were insufficiently powerful enough to operate alone, resulting to combustion motors using fossil fuels for almost a third of the travel covered in electric mode.

Regulatory and Financial Implications

Based on calculations, the lowballing of PHEV emissions enabled four major automaker companies to escape over €5bn in fines between 2021 and 2023, by falsely simplifying adherence with European Union fleet-average CO₂ targets.

Additionally, drivers of PHEVs could pay approximately €500 extra annually in operating costs than would be estimated under laboratory tests.

“The strong statements that automakers often promote about their PHEV vehicles are clearly way off the mark,” stated a transport expert. “Consumers are being duped into thinking that by buying a PHEV, they are helping the planet and cutting costs. In reality, PHEVs are only slightly better than standard petrol and diesel vehicles in terms of energy consumption, CO₂ production, and operating costs.”

Policy Debate and Automotive Lobbying

Hybrid cars have lately been drawn back into political debates as carmakers have lobbied the EU to relax CO₂ standards. A proposed prohibition on new combustion engine cars in 2035 has faced intense lobbying from the car industry and resistance from member states with significant automotive manufacturing.

Some senior officials have suggested plug-in hybrids as a possible “flexibility” option to include in the regulation.

An external energy economics specialist, who was unaffiliated with the study, described the report a “very useful contribution” after a long period in which segments of the automotive sector claimed there was too little data to properly evaluate actual emissions.

“The results show, beyond any doubt, that the gap in lab and real-world PHEV fuel consumption and CO₂ emissions is much, much larger than for gasoline or diesel vehicles,” they stated. “All policy changes regarding PHEVs should be implemented with utmost caution and considering that evidence.”