Plug-in Hybrid electric Vehicles Emit Nearly as Heavily as Petrol Cars, Report Reveals

Plug-in hybrid cars produce nearly 5x more global warming pollution than lab-reported figures show, according to a recent analysis.

Widening Gap In Official and Real-World Emissions

Statistics reveals that PHEVs release only 19% lower CO₂ than traditional petrol and diesel cars, based on analysis carried out by a non-profit organization. That contrasts sharply with lab estimates, which assumed a three-quarters decrease in pollution.

Analysts studied data from onboard fuel consumption monitors of eight hundred thousand cars sold in the EU between 2021 and 2023. The team found that real-world CO₂ output from PHEVs in 2023 were 4.9 times higher than official figures, increased from three and a half times in 2021.

“Actual emissions are rising, while lab-reported figures are decreasing,” stated a senior researcher involved in the report. “This gap is growing and creates a significant issue. Consequently, PHEVs emit almost as much as gasoline vehicles.”

Key Reasons Behind the Discrepancy

Researchers linked the majority of the difference to overestimates of the “electric driving share” – the percentage of kilometers travelled in electric power relative to overall distance. They found that just a quarter of driving was completed in electric mode, while lab estimates assumed 84%.

Additionally, when running in electric mode, emission levels were well above lab projections. That happened because EV motors were not strong enough to function independently, resulting to engines burning fossil fuels for almost one-third of the distance completed in electric mode.

Policy and Financial Implications

Based on calculations, the lowballing of PHEV emissions enabled several large carmaker companies to avoid over €5bn in penalties between 2021 and 2023, by falsely easing adherence with European Union fleet-average CO₂ targets.

Additionally, drivers of PHEVs could pay approximately €500 more per year in running expenses than would be estimated under laboratory tests.

“The strong statements that automakers often promote about their PHEV cars are obviously way off the mark,” commented a transport expert. “Consumers are being misled into thinking that by buying a PHEV, they are helping the environment and cutting costs. Actually, PHEVs are little better than standard gas and diesel cars in terms of fuel consumption, CO₂ production, and operating costs.”

Political Discussion and Industry Pressure

Hybrid vehicles have recently been brought again into policy debates as carmakers have lobbied the European Union to weaken CO₂ standards. A proposed ban on sales of new internal combustion cars in 2035 has faced heavy lobbying from the automotive industry and resistance from member states with large automotive industries.

Several senior politicians have suggested PHEVs as a potential “flexibility” solution to include in the regulation.

An independent energy economics specialist, who was unaffiliated with the study, described the analysis a “highly valuable contribution” after years in which parts of the car sector argued there was too little data to properly evaluate real-world emissions.

“The results show, without question, that the gap in official and actual PHEV fuel consumption and CO₂ output is significantly greater than for gasoline or diesel cars,” the expert stated. “Any regulatory changes regarding PHEVs should be made with utmost caution and in the light of that evidence.”