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

Plug-in hybrid cars produce nearly five times greater planet-heating pollution than official figures indicate, according to a recent analysis.

Growing Discrepancy Between Lab and Actual Emissions

Statistics shows that PHEVs release only one-fifth lower CO₂ than traditional gas and diesel vehicles, based on research carried out by a non-profit group. This contrasts significantly with laboratory estimates, which assumed a three-quarters decrease in emissions.

Analysts studied information from in-vehicle energy use monitors of eight hundred thousand cars registered in Europe from 2021 and 2023. The team found that real-world CO₂ emissions from PHEVs in 2023 were 4.9 times higher than official figures, increased from three and a half times in 2021.

“Actual CO2 output are increasing, while lab-reported emissions are decreasing,” stated a senior researcher participating in the report. “That discrepancy is widening and creates a serious issue. As a result, PHEVs pollute almost as much as petrol cars.”

Primary Reasons Driving the Discrepancy

Researchers attributed the majority of the difference to inflated estimates of the “utility factor” – the percentage of kilometers driven in battery power compared to overall distance. The team determined that just a quarter of driving was done in EV mode, while official assumptions suggested 84%.

Even, when operating in electric mode, emission amounts were well above official estimates. This occurred because EV motors were insufficiently powerful enough to operate independently, resulting to combustion motors burning gasoline for almost one-third of the distance covered in EV mode.

Policy and Economic Consequences

According to calculations, the lowballing of PHEV CO2 output enabled several major automaker companies to escape over €5bn in fines from 2021 and 2023, by artificially simplifying adherence with EU average fleet CO₂ standards.

Furthermore, drivers of PHEVs could spend approximately €500 extra annually in operating expenses than would be estimated under lab tests.

“The strong statements that manufacturers often promote about their PHEV vehicles are obviously way off the mark,” commented a automotive analyst. “Buyers are being misled into believing that by purchasing a PHEV, they are helping the planet and cutting costs. In reality, PHEVs are only slightly better than regular petrol and diesel cars in terms of fuel consumption, CO₂ emissions, and operating expenses.”

Policy Debate and Automotive Lobbying

Plug-in hybrid vehicles have recently been brought again into political discussions as automakers have pressed the EU to relax CO₂ standards. A proposed ban on new combustion engine cars in 2035 has faced intense pressure from the car sector and resistance from EU countries with large automotive industries.

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

An independent energy economics expert, who was unaffiliated with the research, called the report a “highly valuable contribution” after a long period in which parts of the car sector claimed there was too little data to properly evaluate actual CO2 output.

“These findings show, without question, that the gap in lab and real-world PHEV fuel consumption and CO₂ output is much, much greater than for petrol or conventional cars,” the expert stated. “Any policy adjustments regarding PHEVs should be implemented with extreme caution and in the light of this data.”