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

Growing Discrepancy In Official and Actual CO2 Output

Data reveals that PHEVs emit just one-fifth lower CO₂ than traditional petrol and diesel vehicles, according to research conducted by a advocacy group. That contrasts sharply with lab tests, which suggested a 75% reduction in emissions.

Researchers examined data from onboard energy use meters of 800,000 cars sold in Europe between 2021 and 2023. They found that actual CO₂ emissions from PHEVs in 2023 were nearly five times greater than lab figures, increased from 3.5 times in 2021.

“Actual CO2 output are rising, while official figures are decreasing,” stated a senior researcher participating in the study. “This gap is growing and creates a serious issue. As a result, PHEVs emit nearly as heavily as petrol cars.”

Primary Factors Driving the Discrepancy

Analysts linked most of the difference to overestimates of the “utility factor” – the percentage of miles travelled in electric power compared to total mileage. The team found that just 27% of travel was completed in electric mode, while lab assumptions suggested 84%.

Even, when running in electric mode, pollution amounts were well above lab estimates. That occurred because electric motors were insufficiently powerful sufficient to operate independently, leading to combustion motors burning fossil fuels for almost a third of the travel completed in EV mode.

Policy and Financial Implications

According to calculations, the underestimation of PHEV CO2 output enabled several large carmaker companies to escape over €5bn in penalties between 2021 and 2023, by falsely easing adherence with EU fleet-average CO₂ standards.

Furthermore, drivers of PHEVs would spend approximately €500 more per year in operating expenses than would be assumed under lab conditions.

“The bold statements that manufacturers like to make about their PHEV vehicles are clearly way off the mark,” commented a transport expert. “Buyers are being misled into thinking that by buying a PHEV, they are helping the planet and saving costs. Actually, PHEVs are only slightly improved than standard petrol and diesel vehicles in terms of energy use, CO₂ production, and operating expenses.”

Policy Debate and Automotive Pressure

Hybrid vehicles have recently been brought back into policy debates as automakers have lobbied the EU to relax CO₂ targets. A proposed prohibition on new internal combustion cars in 2035 has faced intense pressure from the automotive industry and resistance from member states with significant automotive industries.

Several senior officials have suggested PHEVs as a possible “flexibility” solution to include in the legislation.

An independent energy policy specialist, who was not involved with the study, called the analysis a “very useful addition” after years in which segments of the car industry claimed there was insufficient information to properly assess real-world emissions.

“The results demonstrate, beyond any doubt, that the difference between lab and actual PHEV energy use and CO₂ output is significantly larger than for petrol or diesel cars,” the expert stated. “Any regulatory adjustments regarding PHEVs should be implemented with utmost caution and considering this data.”