Plug in Hybrid Vehicles Pollute Nearly as Much as Petrol Vehicles, Study Reveals

Plug-in hybrid electric vehicles emit almost 5x more global warming pollution than official figures show, as per a new analysis.

Growing Discrepancy Between Lab and Real-World Emissions

Statistics shows that PHEVs emit just one-fifth lower CO₂ than conventional petrol and diesel vehicles, based on research conducted by a advocacy organization. This differs sharply with lab tests, which assumed a 75% reduction in pollution.

Researchers examined data from onboard fuel consumption meters of 800,000 vehicles registered in Europe between 2021 and 2023. The team found that actual CO₂ output from PHEVs in 2023 were nearly five times higher than official figures, up from three and a half times in 2021.

“Real-world emissions are increasing, while official figures are decreasing,” said a senior analyst involved in the report. “That discrepancy is growing and poses a serious issue. Consequently, PHEVs emit nearly as much as gasoline vehicles.”

Primary Factors Driving the Discrepancy

Researchers attributed the majority of the difference to inflated estimates of the “electric driving share” – the percentage of miles driven in electric power compared to overall mileage. The team determined that just a quarter of travel was completed in electric mode, while official assumptions suggested over four-fifths.

Even, when operating in electric mode, pollution levels were well above official projections. That happened because electric motors were insufficiently powerful enough to operate independently, resulting to combustion motors using fossil fuels for almost a third of the distance covered in electric mode.

Policy and Financial Consequences

According to calculations, the underestimation of PHEV CO2 output allowed four large carmaker companies to avoid more than €5bn in penalties from 2021 and 2023, by falsely simplifying compliance with EU average fleet CO₂ targets.

Furthermore, owners of PHEVs could pay about €500 more annually in running expenses than is assumed under lab conditions.

“The strong statements that automakers like to make about their plug-in hybrid vehicles are clearly far from the mark,” commented a automotive analyst. “Consumers are being duped into believing that by purchasing a PHEV, they are benefiting the planet and cutting money. Actually, PHEVs are little improved than standard petrol and diesel cars in terms of energy use, CO₂ emissions, and running expenses.”

Political Discussion and Industry Lobbying

Plug-in hybrid cars have recently been drawn back into political debates as carmakers have lobbied the European Union to relax CO₂ targets. A planned prohibition on new internal combustion vehicles in 2035 has faced intense lobbying from the car sector and resistance from member states with large car manufacturing.

Some high-level politicians have proposed PHEVs as a potential “flexibility” solution to include in the regulation.

One independent energy economics expert, who was unaffiliated with the study, called the report a “highly valuable addition” after a long period in which segments of the car industry claimed there was too little information to properly assess real-world CO2 output.

“These findings show, beyond any doubt, that the gap in lab and real-world PHEV fuel consumption and CO₂ emissions is significantly larger than for gasoline or conventional vehicles,” they stated. “Any policy adjustments concerning PHEVs should be made with extreme caution and in the light of that data.”