🔗 Share this article Plug-in Hybrid Cars Pollute Nearly as Much as Petrol Vehicles, Study Finds Plug-in hybrid electric vehicles produce nearly five times more global warming emissions than official data indicate, according to a new report. Widening Gap In Official and Real-World Emissions Statistics shows that PHEVs release just one-fifth lower CO2 than conventional gas and diesel cars, according to research carried out by a non-profit group. This contrasts significantly with lab estimates, which suggested a 75% reduction in pollution. Researchers studied data from in-vehicle fuel consumption meters of 800,000 vehicles sold in the EU between 2021 and 2023. They discovered that actual CO2 emissions from PHEVs in 2023 were 4.9 times greater than lab figures, increased from three and a half times in 2021. “Real-world emissions are increasing, while official figures are falling,” stated a senior researcher involved in the report. “That discrepancy is growing and creates a significant problem. As a result, PHEVs emit almost as heavily as gasoline vehicles.” Key Factors Behind the Discrepancy Researchers linked most of the difference to overestimates of the “utility factor” – the percentage of miles travelled in battery power compared to overall mileage. They determined that just 27% of travel was completed in EV mode, while lab assumptions assumed 84%. Additionally, when running in EV mode, emission levels were significantly higher than lab projections. That happened because electric motors were not strong enough to function alone, leading to engines using fossil fuels for almost one-third of the distance completed in EV mode. Regulatory and Financial Consequences According to calculations, the underestimation of PHEV CO2 output enabled four major automaker groups to escape over €5bn in penalties between 2021 and 2023, by falsely simplifying adherence with EU average fleet CO2 standards. Furthermore, drivers of PHEVs would pay about €500 more per year in operating expenses than would be estimated under lab conditions. “The strong statements that automakers like to make about their plug-in hybrid vehicles are obviously way off the mark,” stated a transport analyst. “Consumers are being misled into thinking that by buying a PHEV, they are benefiting the environment and saving costs. In reality, PHEVs are little improved than standard gas and diesel vehicles in terms of energy consumption, CO2 production, and running costs.” Political Discussion and Automotive Pressure Plug-in hybrid vehicles have lately been brought back into political discussions as carmakers have pressed the European Union to weaken CO2 standards. A proposed prohibition on new internal combustion vehicles in 2035 has faced intense pressure from the car industry and resistance from EU countries with significant automotive industries. Several senior officials have proposed PHEVs as a potential “compromise” option to introduce in the legislation. An independent energy policy expert, who was not involved with the study, called the report a “very useful addition” after years in which segments of the automotive industry argued there was too little information to properly assess actual emissions. “The results show, without question, that the difference between official and real-world PHEV fuel consumption and CO2 emissions is much, much greater than for gasoline or diesel vehicles,” the expert said. “Any regulatory adjustments concerning PHEVs should be implemented with extreme caution and in the light of that data.”