Plug in Hybrid Cars Pollute Nearly as Much as Petrol Cars, Study Finds

Plug-in hybrid cars emit nearly five times greater global warming pollution than lab-reported figures show, as per a new report.

Growing Discrepancy Between Official and Actual CO2 Output

Data shows that PHEVs release just 19% lower CO₂ than traditional petrol and diesel vehicles, according to analysis carried out by a advocacy organization. That differs significantly with lab tests, which assumed a 75% reduction in pollution.

Researchers examined data from onboard fuel consumption meters of eight hundred thousand cars registered in Europe between 2021 and 2023. They found that actual CO₂ output from PHEVs in 2023 were nearly five times higher than lab figures, up from 3.5 times in 2021.

“Real-world CO2 output are increasing, while official figures are decreasing,” said a lead analyst participating in the study. “That gap is growing and creates a significant problem. Consequently, PHEVs pollute almost as much as petrol cars.”

Primary Factors Behind the Discrepancy

Analysts linked the majority of the gap to overestimates of the “electric driving share” – the percentage of kilometers travelled in electric power compared to overall mileage. They determined that just a quarter of travel was completed in electric mode, whereas official assumptions assumed over four-fifths.

Additionally, when operating in EV mode, emission levels were significantly higher than official projections. That occurred because EV motors were not strong sufficient to function alone, leading to engines using gasoline for nearly one-third of the travel covered in electric mode.

Policy and Economic Consequences

According to calculations, the lowballing of PHEV CO2 output allowed several major carmaker companies to escape more than €5bn in penalties between 2021 and 2023, by falsely simplifying compliance with European Union average fleet CO₂ standards.

Furthermore, drivers of PHEVs would spend approximately €500 extra annually in operating expenses than is assumed under lab conditions.

“The bold statements that automakers like to make about their PHEV vehicles are clearly way off the mark,” commented a automotive expert. “Buyers are being duped into believing that by buying a PHEV, they are helping the planet and saving costs. Actually, PHEVs are little better than regular petrol and diesel cars in terms of energy use, CO₂ production, and operating costs.”

Policy Debate and Industry Pressure

Plug-in hybrid cars have lately been drawn again into policy discussions as carmakers have pressed the European Union to weaken CO₂ targets. A planned ban on new internal combustion cars in 2035 has faced intense pressure from the car sector and resistance from EU countries with significant automotive industries.

Several high-level politicians have proposed plug-in hybrids as a possible “flexibility” option to introduce in the legislation.

An external energy economics specialist, who was unaffiliated with the research, called the report a “very useful contribution” after years in which parts of the car industry argued there was insufficient data to properly assess actual emissions.

“These findings demonstrate, without question, that the difference in official and actual PHEV energy use and CO₂ output is significantly greater than for gasoline or diesel cars,” they stated. “Any policy changes regarding PHEVs should be implemented with utmost caution and in the light of that evidence.”