Plug in Hybrid Vehicles Pollute Almost as Heavily as Petrol Cars, Report Finds

Plug-in hybrid cars release almost five times more global warming emissions than lab-reported figures indicate, as per a recent report.

Growing Gap Between Lab and Real-World CO2 Output

Data reveals that PHEVs release only 19% less CO₂ than traditional gas and diesel vehicles, according to research carried out by a non-profit group. That differs sharply with lab estimates, which suggested a three-quarters reduction in emissions.

Researchers examined information from in-vehicle fuel consumption monitors of 800,000 cars registered in the EU between 2021 and 2023. They found that real-world CO₂ emissions from PHEVs in 2023 were nearly five times higher than lab estimates, increased from 3.5 times in 2021.

“Real-world CO2 output are rising, while official figures are decreasing,” stated a senior researcher participating in the study. “This gap is growing and poses a significant issue. Consequently, PHEVs pollute nearly as much as gasoline vehicles.”

Primary Reasons Driving the Emissions Gap

Analysts attributed the majority of the gap to overestimates of the “electric driving share” – the percentage of kilometers driven in electric power compared to total distance. They determined that just 27% of driving was done in EV mode, while official assumptions assumed over four-fifths.

Additionally, when operating in electric mode, pollution amounts were significantly higher than lab projections. That happened because EV motors were insufficiently powerful sufficient to operate alone, resulting to combustion motors using fossil fuels for nearly a third of the distance covered in EV mode.

Policy and Economic Implications

According to estimates, the lowballing of PHEV CO2 output allowed several large automaker companies to escape over €5bn in penalties between 2021 and 2023, by artificially easing adherence with European Union fleet-average CO₂ standards.

Additionally, drivers of PHEVs would spend about €500 extra annually in running costs than is assumed under lab tests.

“The bold claims that automakers often promote about their PHEV vehicles are obviously far from the mark,” stated a transport expert. “Buyers are being misled into believing that by buying a PHEV, they are benefiting the planet and cutting money. In reality, PHEVs are little improved than regular petrol and diesel vehicles in terms of fuel consumption, CO₂ production, and running expenses.”

Policy Discussion and Automotive Pressure

Plug-in hybrid cars have recently been drawn again into political debates as automakers have pressed the EU to weaken CO₂ targets. A proposed prohibition on sales of new internal combustion cars in 2035 has faced intense pressure from the car sector and resistance from EU countries with significant car manufacturing.

Several high-level officials have proposed PHEVs as a possible “compromise” option to introduce in the regulation.

An independent energy economics specialist, who was not involved with the research, called the report a “very useful addition” after years in which segments of the automotive industry claimed there was too little data to properly assess actual CO2 output.

“The results demonstrate, without question, that the difference in official and real-world PHEV energy use and CO₂ emissions is much, much greater than for petrol or diesel vehicles,” they said. “All regulatory changes regarding PHEVs should be made with extreme caution and in the light of this data.”