Plug-in Hybrid electric Cars Emit Almost as Much as Gasoline Vehicles, Report Finds
Plug-in hybrid electric vehicles emit nearly five times more planet-heating emissions than official figures indicate, as per a recent report.
Widening Discrepancy Between Lab and Real-World CO2 Output
Statistics reveals that PHEVs emit only 19% less CO2 than conventional petrol and diesel cars, based on analysis conducted by a non-profit organization. This differs sharply with lab estimates, which assumed a three-quarters decrease in emissions.
Analysts examined data from in-vehicle fuel consumption monitors of eight hundred thousand vehicles registered in Europe from 2021 and 2023. They discovered that actual CO2 output from PHEVs in 2023 were nearly five times greater than lab figures, up from 3.5 times in 2021.
“Real-world CO2 output are rising, while lab-reported emissions are decreasing,” stated a lead researcher involved in the study. “That discrepancy is widening and poses a significant issue. Consequently, PHEVs emit almost as much as petrol cars.”
Primary Factors Driving the Discrepancy
Researchers attributed most of the difference to overestimates of the “utility factor” – the ratio of miles driven in battery mode relative to total mileage. The team found that just 27% of travel was completed in EV mode, whereas lab estimates assumed 84%.
Even, when operating in electric mode, emission amounts were well above official estimates. That happened because EV motors were not strong enough to function independently, leading to combustion motors using gasoline for nearly one-third of the travel completed in EV mode.
Regulatory and Economic Consequences
According to estimates, the lowballing of PHEV emissions enabled several large carmaker groups to escape over €5bn in penalties between 2021 and 2023, by artificially simplifying adherence with EU fleet-average CO2 standards.
Furthermore, owners of PHEVs could pay about €500 extra per year in operating expenses than would be estimated under lab tests.
“The bold statements that manufacturers like to make about their plug-in hybrid vehicles are clearly far from the truth,” stated a transport expert. “Consumers are being misled into thinking that by buying a PHEV, they are helping the environment and saving money. Actually, PHEVs are little improved than standard petrol and diesel cars in terms of fuel consumption, CO2 production, and running expenses.”
Policy Discussion and Industry Pressure
Hybrid cars have recently been brought again into policy debates as carmakers have pressed the EU to relax CO2 targets. A planned prohibition on sales of new combustion engine vehicles in 2035 has faced intense lobbying from the car industry and resistance from member states with significant car manufacturing.
Some high-level officials have suggested plug-in hybrids as a possible “compromise” option to introduce in the regulation.
An external energy economics expert, who was unaffiliated with the research, called the report a “highly valuable contribution” after years in which segments of the automotive sector claimed there was too little information to properly evaluate actual emissions.
“These findings demonstrate, beyond any doubt, that the gap between official and actual PHEV energy use and CO2 emissions is much, much larger than for gasoline or diesel vehicles,” the expert said. “Any regulatory changes concerning PHEVs should be implemented with utmost caution and considering that data.”
