🔗 Share this article Plug in Hybrid Cars Pollute Almost as Heavily as Petrol Vehicles, Study Finds Plug-in hybrid cars emit almost 5x more planet-heating emissions than lab-reported data show, according to a new analysis. Widening Discrepancy Between Lab and Actual Emissions Data reveals that PHEVs release only one-fifth less CO2 than conventional petrol and diesel vehicles, based on analysis conducted by a advocacy organization. That differs sharply with laboratory tests, which suggested a three-quarters decrease in pollution. Researchers examined data from onboard fuel consumption monitors of 800,000 cars registered in Europe between 2021 and 2023. They discovered that actual CO2 emissions from PHEVs in 2023 were 4.9 times higher than lab estimates, up from 3.5 times in 2021. “Actual CO2 output are rising, while official emissions are decreasing,” said a lead analyst participating in the study. “That discrepancy is growing and creates a serious problem. As a result, PHEVs emit almost as much as petrol cars.” Key Reasons Driving the Emissions Gap Analysts linked most of the difference to overestimates of the “electric driving share” – the percentage of kilometers driven in battery mode relative to overall distance. They found that only a quarter of travel was completed in electric mode, while lab assumptions assumed over four-fifths. Even, when running in EV mode, pollution amounts were significantly higher than lab estimates. This occurred because EV motors were insufficiently powerful sufficient to operate independently, leading to combustion motors burning gasoline for nearly one-third of the travel completed in electric mode. Regulatory and Financial Consequences According to calculations, the lowballing of PHEV emissions enabled several large carmaker groups to avoid over €5bn in fines from 2021 and 2023, by artificially simplifying adherence with EU fleet-average CO2 targets. Additionally, drivers of PHEVs could spend approximately €500 more per year in operating expenses than would be estimated under laboratory conditions. “The strong claims that manufacturers like to make about their plug-in hybrid cars are clearly far from the mark,” stated a automotive analyst. “Consumers are being duped into believing that by buying a PHEV, they are benefiting the environment and cutting money. Actually, PHEVs are little improved than regular gas and diesel cars in terms of energy consumption, CO2 emissions, and running costs.” Policy Discussion and Automotive Pressure Plug-in hybrid cars have lately been brought back into policy debates as carmakers have lobbied the EU to relax CO2 standards. A planned ban on sales of new internal combustion vehicles in 2035 has faced heavy lobbying from the automotive sector and opposition from member states with large car industries. Some senior officials have proposed plug-in hybrids as a potential “compromise” option to include in the regulation. An external energy policy expert, who was not involved with the study, called the analysis a “very useful addition” after years in which segments of the car sector claimed there was insufficient data to accurately assess actual emissions. “The results show, beyond any doubt, that the gap in lab and real-world PHEV energy use and CO2 emissions is significantly larger than for gasoline or diesel cars,” the expert stated. “Any policy adjustments concerning PHEVs should be implemented with utmost care and considering this data.”