Plug-in Hybrid electric Cars Emit Almost as Heavily as Petrol Cars, Study Finds
Plug-in hybrid cars release nearly 5x more planet-heating emissions than official figures show, according to a new report.
Growing Discrepancy In Lab and Real-World Emissions
Data shows that PHEVs emit only one-fifth less CO2 than conventional petrol and diesel cars, according to research conducted by a non-profit group. This contrasts sharply with lab estimates, which suggested a three-quarters decrease in emissions.
Researchers examined data from onboard energy use monitors of eight hundred thousand vehicles sold in Europe from 2021 and 2023. The team discovered that actual CO2 output from PHEVs in 2023 were 4.9 times greater than official estimates, increased from three and a half times in 2021.
“Real-world emissions are increasing, while lab-reported emissions are decreasing,” stated a senior analyst participating in the study. “That discrepancy is growing and poses a serious problem. Consequently, PHEVs pollute nearly as heavily as petrol vehicles.”
Primary Reasons Behind the Emissions Gap
Analysts attributed the majority of the difference to overestimates of the “electric driving share” – the percentage of kilometers travelled in battery power relative to total mileage. They found that only 27% of driving was done in electric mode, whereas official estimates suggested 84%.
Additionally, when running in electric mode, pollution amounts were significantly higher than official projections. That happened because EV motors were not strong sufficient to operate alone, leading to engines burning gasoline for almost a third of the travel covered in EV mode.
Policy and Financial Implications
According to estimates, the lowballing of PHEV emissions enabled four major automaker groups to escape more than €5bn in fines from 2021 and 2023, by artificially easing adherence with EU average fleet CO2 targets.
Additionally, drivers of PHEVs could spend approximately €500 extra per year in running costs than is assumed under lab tests.
“The bold claims that manufacturers often promote about their plug-in hybrid vehicles are obviously way off the truth,” stated a automotive analyst. “Consumers are being misled into thinking that by buying a PHEV, they are helping the environment and saving costs. Actually, PHEVs are little improved than regular gas and diesel cars in terms of fuel use, CO2 emissions, and operating costs.”
Policy Debate and Industry Lobbying
Plug-in hybrid cars have lately been drawn again into political discussions as automakers have lobbied the European Union to weaken CO2 standards. A planned prohibition on sales of new internal combustion vehicles in 2035 has faced intense lobbying from the automotive industry and resistance from EU countries with significant car industries.
Several senior officials have proposed plug-in hybrids as a possible “flexibility” option to include in the regulation.
One external energy policy specialist, who was not involved with the study, described the report a “very useful addition” after years in which segments of the automotive industry claimed there was insufficient information to accurately assess real-world CO2 output.
“These findings show, without question, that the difference between lab and actual PHEV energy use and CO2 emissions is significantly larger than for petrol or diesel vehicles,” they stated. “All regulatory adjustments concerning PHEVs should be implemented with extreme care and in the light of this data.”
