A new study by the International Council on Clean Transportation (ICCT), released on September 3, reveals that plug-in hybrid vehicles emit five times more carbon dioxide (CO2) than the official figures reported by the European Union. These vehicles, which use both a traditional internal combustion engine and an electric motor, were previously considered a greener alternative to fully electric or conventional cars. However, the study highlights that plug-in hybrids are not often charged using electric stations, leading to more frequent use of their fuel or diesel engines. This reliance on traditional engines results in higher emissions than previously thought. The ICCT's research also points out that plug-in hybrids are typically larger and heavier vehicles due to the added weight of their batteries. This makes them less efficient when operating solely on the thermal engine, which consumes more fuel than expected. Pierre-Olivier Marie, deputy editor-in-chief of the French automotive website Caradisiac, described these vehicles as "a true glutton, a fuel pit," emphasizing their high fuel consumption when not using electric power. Plug-in hybrids are often high-end models, with an average price of over 30,000 euros. Despite their higher cost, these vehicles account for 6 percent of new car sales in France since the start of the year. The findings from the ICCT challenge the perception of these cars as environmentally friendly and may prompt consumers and policymakers to reconsider their role in reducing transportation-related emissions. The study underscores the importance of accurate emissions data in shaping effective climate policies. As the automotive industry continues to transition toward greener technologies, the findings suggest that the environmental benefits of plug-in hybrids may be overestimated, particularly when they are not regularly charged using electric power. This raises questions about their overall contribution to reducing greenhouse gas emissions in the transportation sector.