Plug in Hybrid Cars Pollute Nearly as Heavily as Gasoline Vehicles, Report Reveals

Plug-in hybrid cars release almost 5x greater global warming pollution than lab-reported figures indicate, as per a recent analysis.

Widening Discrepancy In Official and Real-World CO2 Output

Data shows that PHEVs release only 19% less CO₂ than traditional gas and diesel vehicles, based on research carried out by a non-profit organization. That differs sharply with lab estimates, which suggested a 75% reduction in pollution.

Researchers studied information from in-vehicle energy use monitors of 800,000 vehicles registered in Europe from 2021 and 2023. The team found that actual CO₂ emissions from PHEVs in 2023 were nearly five times greater than lab estimates, increased from three and a half times in 2021.

“Real-world CO2 output are increasing, while official emissions are decreasing,” stated a lead researcher participating in the study. “This discrepancy is widening and creates a significant problem. Consequently, PHEVs pollute almost as much as gasoline vehicles.”

Primary Reasons Behind the Emissions Gap

Analysts attributed the majority of the gap to overestimates of the “electric driving share” – the percentage of miles travelled in battery mode compared to total distance. They determined that just a quarter of travel was done in electric mode, while lab estimates assumed 84%.

Even, when running in EV mode, pollution amounts were significantly higher than lab estimates. That happened because electric motors were not strong enough to operate independently, resulting to engines burning gasoline for almost a third of the distance completed in EV mode.

Policy and Financial Implications

According to estimates, the lowballing of PHEV emissions allowed several large carmaker groups to avoid more than €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 annually in operating costs than is assumed under lab tests.

“The strong statements that manufacturers often promote about their PHEV cars are clearly far from the truth,” commented a automotive expert. “Buyers are being duped into believing that by purchasing a PHEV, they are helping the planet and cutting costs. Actually, PHEVs are only slightly improved than standard gas and diesel cars in terms of fuel consumption, CO₂ emissions, and operating expenses.”

Policy Discussion and Industry Pressure

Hybrid cars have recently been drawn again into political debates as automakers have lobbied the European Union to weaken CO₂ targets. A planned prohibition on new combustion engine vehicles in 2035 has faced intense lobbying from the car industry and opposition from EU countries with large automotive manufacturing.

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

An external energy economics specialist, who was not involved with the study, described the analysis a “very useful addition” after years in which segments of the automotive sector claimed there was insufficient data to accurately assess real-world CO2 output.

“These findings demonstrate, beyond any doubt, that the difference between official and real-world PHEV energy use and CO₂ emissions is significantly larger than for petrol or conventional vehicles,” the expert stated. “Any regulatory changes regarding PHEVs should be made with extreme caution and in the light of this evidence.”