Plug-in Hybrid Cars Emit Almost as Much as Petrol Vehicles, Report Reveals

Plug-in hybrid cars release nearly five times more global warming pollution than lab-reported data indicate, as per a new report.

Growing Gap In Lab and Real-World CO2 Output

Data reveals that PHEVs emit only one-fifth lower CO₂ than conventional petrol and diesel vehicles, based on research conducted by a advocacy organization. That differs significantly with laboratory tests, which assumed a 75% reduction in emissions.

Researchers studied data from in-vehicle fuel consumption meters of eight hundred thousand vehicles registered in Europe between 2021 and 2023. The team found that real-world CO₂ emissions from PHEVs in 2023 were 4.9 times higher than lab figures, increased from 3.5 times in 2021.

“Actual emissions are increasing, while official figures are decreasing,” said a lead analyst involved in the report. “That discrepancy is growing and poses a serious issue. As a result, PHEVs emit nearly as heavily as petrol vehicles.”

Key Reasons Behind the Emissions Gap

Analysts linked most of the difference to inflated estimates of the “utility factor” – the percentage of kilometers driven in electric power compared to total mileage. The team determined that just a quarter of travel was completed in electric mode, whereas lab assumptions assumed 84%.

Even, when running in EV mode, emission levels were well above official projections. This occurred because EV motors were insufficiently powerful enough to function alone, resulting to combustion motors using gasoline for almost one-third of the distance covered in EV mode.

Policy and Economic Consequences

According to estimates, the lowballing of PHEV CO2 output enabled four major carmaker companies to escape more than €5bn in penalties from 2021 and 2023, by falsely simplifying adherence with EU fleet-average CO₂ targets.

Additionally, drivers of PHEVs could pay approximately €500 more per year in running costs than is assumed under laboratory tests.

“The bold statements that automakers often promote about their plug-in hybrid cars are clearly way off the mark,” stated a transport expert. “Consumers are being duped into thinking that by purchasing a PHEV, they are helping the environment and saving money. In reality, PHEVs are only slightly better than regular gas and diesel vehicles in terms of energy consumption, CO₂ emissions, and running costs.”

Political Debate and Automotive Pressure

Hybrid cars have lately been brought again into political debates as carmakers have lobbied the EU to relax CO₂ standards. A planned ban on new combustion engine vehicles in 2035 has faced intense lobbying from the car sector and opposition from EU countries with large automotive manufacturing.

Several high-level officials have suggested plug-in hybrids as a potential “compromise” solution to introduce in the regulation.

An external energy policy expert, who was not involved with the study, described the report a “very useful contribution” after years in which segments of the automotive industry claimed there was too little information to accurately assess actual emissions.

“These findings demonstrate, without question, that the gap in lab and actual PHEV energy use and CO₂ output is much, much greater than for gasoline or diesel cars,” the expert said. “All regulatory changes concerning PHEVs should be made with extreme caution and in the light of this evidence.”