Plug-in Hybrid electric Cars Emit Almost as Much as Petrol Vehicles, Report Reveals
Plug-in hybrid cars release nearly 5x more planet-heating emissions than official data indicate, according to a new analysis.
Widening Discrepancy In Lab and Real-World Emissions
Statistics shows that PHEVs emit only one-fifth lower CO2 than conventional petrol and diesel cars, according to analysis conducted by a non-profit group. That differs significantly with laboratory tests, which suggested a three-quarters reduction in emissions.
Researchers examined information from onboard fuel consumption monitors of 800,000 vehicles registered in Europe between 2021 and 2023. The team discovered that actual CO2 emissions from PHEVs in 2023 were nearly five times higher than official figures, up from 3.5 times in 2021.
“Real-world emissions are increasing, while lab-reported emissions are decreasing,” said a senior analyst involved in the report. “That discrepancy is widening and poses a serious problem. Consequently, PHEVs pollute almost as much as gasoline vehicles.”
Key Factors Driving the Discrepancy
Analysts attributed the majority of the difference to inflated estimates of the “electric driving share” – the percentage of miles driven in battery mode compared to total mileage. The team determined that only a quarter of driving was done in EV mode, whereas lab estimates assumed 84%.
Even, when operating in EV mode, pollution levels were well above lab estimates. This occurred because electric motors were insufficiently powerful enough to operate independently, resulting to combustion motors using fossil fuels for nearly a third of the distance completed in electric mode.
Regulatory and Economic Consequences
Based on calculations, the underestimation of PHEV CO2 output enabled several major automaker companies to escape over €5bn in fines from 2021 and 2023, by falsely simplifying compliance with European Union average fleet CO2 targets.
Furthermore, owners of PHEVs could spend about €500 extra per year in running expenses than would be estimated under laboratory tests.
“The strong statements that automakers often promote about their plug-in hybrid vehicles are obviously way off the mark,” commented a automotive expert. “Buyers are being misled into believing that by buying a PHEV, they are helping the environment and saving money. In reality, PHEVs are only slightly better than standard gas and diesel vehicles in terms of energy use, CO2 emissions, and running expenses.”
Political Discussion and Automotive Pressure
Hybrid vehicles have lately been drawn again into policy debates as automakers have pressed the EU to weaken CO2 targets. A proposed ban on sales of new internal combustion vehicles in 2035 has faced intense pressure from the car industry and resistance from member states with significant automotive manufacturing.
Several high-level officials have proposed plug-in hybrids as a potential “compromise” option to introduce in the legislation.
One external energy policy expert, who was not involved with the study, described the report a “highly valuable contribution” after a long period in which parts of the car industry argued there was too little data to properly evaluate actual emissions.
“These findings demonstrate, without question, that the difference between lab and actual PHEV fuel consumption and CO2 output is much, much larger than for gasoline or conventional cars,” the expert said. “Any regulatory changes concerning PHEVs should be implemented with extreme caution and considering that evidence.”
