Plug-in Hybrid Cars Emit Nearly as Heavily as Petrol Cars, Study Finds
Plug-in hybrid electric vehicles produce nearly five times greater planet-heating pollution than official figures indicate, according to a recent report.
Widening Gap Between Lab and Real-World Emissions
Data shows that PHEVs emit only 19% lower CO2 than traditional gas and diesel cars, according to analysis conducted by a advocacy organization. This differs significantly with lab estimates, which suggested a three-quarters decrease in pollution.
Analysts examined information from onboard energy use monitors of eight hundred thousand vehicles sold in the EU from 2021 and 2023. They discovered that actual CO2 output from PHEVs in 2023 were 4.9 times higher than lab figures, increased from three and a half times in 2021.
“Actual CO2 output are rising, while official figures are decreasing,” said a senior researcher participating in the report. “This discrepancy is growing and poses a serious issue. Consequently, PHEVs emit nearly as heavily as petrol cars.”
Primary Reasons Driving the Discrepancy
Researchers linked most of the difference to inflated estimates of the “utility factor” – the percentage of kilometers driven in battery power relative to overall mileage. They found that only 27% of driving was completed in EV mode, while official assumptions suggested over four-fifths.
Even, when operating in EV mode, emission levels were well above lab projections. That happened because electric motors were insufficiently powerful enough to operate independently, leading to combustion motors using fossil fuels for almost one-third of the travel completed in electric mode.
Regulatory and Financial Implications
Based on calculations, the underestimation of PHEV emissions allowed several large carmaker companies to escape more than €5bn in fines from 2021 and 2023, by falsely simplifying adherence with European Union fleet-average CO2 standards.
Furthermore, owners of PHEVs would spend about €500 more annually in running costs than would be estimated under laboratory tests.
“The bold claims that automakers often promote about their plug-in hybrid cars are clearly way off the truth,” stated a automotive expert. “Buyers are being duped into thinking that by buying a PHEV, they are helping the environment and cutting money. Actually, PHEVs are only slightly improved than standard petrol and diesel cars in terms of fuel consumption, CO2 emissions, and operating costs.”
Political Debate and Industry Lobbying
Hybrid vehicles have recently been drawn again into policy discussions as carmakers have lobbied the European Union to relax CO2 targets. A proposed ban on sales of new combustion engine vehicles in 2035 has faced heavy pressure from the automotive industry and opposition from member states with large automotive industries.
Several senior politicians have suggested plug-in hybrids as a potential “compromise” option to introduce in the regulation.
An external energy economics specialist, who was not involved with the study, described the report a “very useful contribution” after a long period in which parts of the automotive sector claimed there was insufficient data to accurately assess real-world CO2 output.
“The results show, beyond any doubt, that the difference in official and real-world PHEV fuel consumption and CO2 emissions is much, much larger than for petrol or conventional vehicles,” the expert said. “All policy adjustments regarding PHEVs should be made with utmost care and considering this data.”
