Plug in Hybrid electric Cars Emit Almost as Heavily as Gasoline Cars, Study Finds

PHEVs emit nearly 5x more global warming emissions than official figures indicate, as per a recent analysis.

Widening Discrepancy In Official and Actual Emissions

Data reveals that PHEVs release only one-fifth less CO₂ than traditional gas and diesel vehicles, according to analysis carried out by a advocacy organization. That differs sharply with laboratory tests, which suggested a three-quarters reduction in pollution.

Analysts examined information from onboard fuel consumption monitors of 800,000 vehicles registered in the EU between 2021 and 2023. They discovered that actual CO₂ emissions from PHEVs in 2023 were nearly five times greater than official estimates, increased from three and a half times in 2021.

“Actual CO2 output are rising, while lab-reported emissions are decreasing,” stated a lead researcher participating in the study. “That gap is widening and creates a serious issue. Consequently, PHEVs emit almost as much as gasoline vehicles.”

Key Reasons Driving the Discrepancy

Researchers linked most of the gap to overestimates of the “utility factor” – the percentage of kilometers travelled in electric mode compared to total mileage. The team found that just a quarter of driving was done in electric mode, while lab assumptions suggested 84%.

Even, when operating in EV mode, pollution levels were significantly higher than official projections. That occurred because EV motors were insufficiently powerful sufficient to operate alone, resulting to combustion motors using fossil fuels for almost one-third of the travel covered in electric mode.

Policy and Financial Implications

Based on estimates, the underestimation of PHEV CO2 output enabled four major carmaker groups to escape more than €5bn in fines between 2021 and 2023, by falsely easing adherence with EU average fleet CO₂ targets.

Additionally, owners of PHEVs would spend approximately €500 more annually in operating expenses than would be assumed under lab conditions.

“The strong statements that manufacturers often promote about their PHEV vehicles are clearly way off the mark,” commented a transport expert. “Consumers are being misled into believing that by purchasing a PHEV, they are helping the planet and cutting costs. In reality, PHEVs are only slightly improved than standard gas and diesel vehicles in terms of energy consumption, CO₂ emissions, and operating expenses.”

Political Debate and Industry Pressure

Hybrid cars have lately been brought again into policy discussions as automakers have pressed the EU to weaken CO₂ targets. A planned ban on sales of new internal combustion cars in 2035 has faced intense lobbying from the automotive sector and resistance from member states with large automotive manufacturing.

Some high-level politicians have proposed plug-in hybrids as a potential “compromise” option to introduce in the regulation.

An external energy policy specialist, who was unaffiliated with the research, called the analysis a “highly valuable addition” after years in which segments of the car industry claimed there was too little data to accurately evaluate real-world CO2 output.

“These findings show, without question, that the difference between lab and real-world PHEV fuel consumption and CO₂ emissions is much, much greater than for petrol or diesel vehicles,” the expert said. “Any policy adjustments concerning PHEVs should be made with utmost caution and in the light of that data.”