Plug-in Hybrid electric Cars Emit Almost as Heavily as Petrol Cars, Study Finds
PHEVs produce nearly 5x more global warming emissions than lab-reported data indicate, according to a recent analysis.
Growing Gap In Official and Actual Emissions
Data reveals that PHEVs release only one-fifth less CO2 than conventional gas and diesel cars, based on research carried out by a non-profit group. This differs significantly with laboratory estimates, which assumed a 75% decrease in emissions.
Analysts studied information from in-vehicle energy use monitors of 800,000 vehicles registered in Europe between 2021 and 2023. They found that real-world CO2 emissions 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 figures are falling,” stated a senior researcher participating in the report. “This discrepancy is growing and creates a serious problem. Consequently, PHEVs pollute almost as heavily as petrol vehicles.”
Primary Factors Driving the Emissions Gap
Researchers linked the majority of the difference to inflated estimates of the “electric driving share” – the percentage of kilometers driven in electric mode compared to total mileage. The team determined that only 27% of driving was completed in electric mode, while official assumptions assumed over four-fifths.
Even, when running in EV mode, pollution amounts were well above lab projections. That happened because EV motors were insufficiently powerful enough to operate alone, resulting to combustion motors burning fossil fuels for almost a third of the travel completed in electric mode.
Regulatory and Economic Implications
Based on estimates, the underestimation of PHEV CO2 output enabled four large automaker companies to escape more than €5bn in fines between 2021 and 2023, by artificially easing compliance with EU average fleet CO2 targets.
Furthermore, drivers of PHEVs would pay about €500 more per year in running expenses than would be estimated under laboratory conditions.
“The strong claims that manufacturers often promote about their PHEV vehicles are clearly far from the mark,” stated a transport expert. “Buyers are being misled into thinking that by purchasing a PHEV, they are helping the planet and cutting money. In reality, PHEVs are only slightly improved than regular gas and diesel vehicles in terms of energy consumption, CO2 production, and running expenses.”
Political Debate and Industry Lobbying
Hybrid vehicles have lately been drawn again into political discussions as automakers have pressed the EU to weaken CO2 targets. A proposed prohibition on sales of new internal combustion vehicles in 2035 has faced heavy lobbying from the car industry and resistance from EU countries with large car industries.
Several high-level politicians have proposed plug-in hybrids as a possible “flexibility” solution to introduce in the legislation.
An external energy policy expert, who was unaffiliated with the research, described the analysis a “highly valuable contribution” after a long period in which segments of the automotive sector argued there was too little data to accurately assess real-world emissions.
“The results show, without question, that the gap between official and actual PHEV fuel consumption and CO2 output is much, much larger than for petrol or diesel vehicles,” they said. “Any policy changes regarding PHEVs should be implemented with extreme care and in the light of that data.”
