🔗 Share this article

Plug-in hybrid electric vehicles produce nearly 5x more global warming pollution than lab-reported data indicate, according to a new report.

Growing Discrepancy Between Lab and Actual Emissions

Statistics reveals that PHEVs emit only 19% lower CO₂ than traditional petrol and diesel vehicles, based on analysis conducted by a non-profit organization. That contrasts sharply with laboratory tests, which assumed a 75% reduction in pollution.

Analysts examined data from in-vehicle energy use meters of eight hundred thousand vehicles registered in the EU from 2021 and 2023. The team discovered that real-world CO₂ output from PHEVs in 2023 were 4.9 times greater than official estimates, increased from 3.5 times in 2021.

“Real-world CO2 output are rising, while lab-reported figures are falling,” stated a senior researcher participating in the report. “This discrepancy is growing and poses a serious issue. As a result, PHEVs emit nearly as heavily as petrol vehicles.”

Key Reasons Behind the Discrepancy

Researchers attributed most of the difference to inflated estimates of the “utility factor” – the percentage of miles driven in electric mode relative to total mileage. They determined that just 27% of driving was done in EV mode, while official estimates assumed 84%.

Even, when running in electric mode, emission amounts were significantly higher than lab estimates. That occurred because electric motors were insufficiently powerful sufficient to function alone, leading to engines burning fossil fuels for nearly one-third of the distance covered in EV mode.

Regulatory and Economic Implications

Based on estimates, the lowballing of PHEV CO2 output enabled several large automaker companies to escape more than €5bn in fines between 2021 and 2023, by falsely simplifying compliance with EU average fleet CO₂ targets.

Additionally, owners of PHEVs would spend approximately €500 more per year in operating costs than is assumed under lab tests.

“The bold statements that automakers like to make about their plug-in hybrid vehicles are clearly far from the mark,” stated a automotive analyst. “Buyers are being misled into thinking that by buying a PHEV, they are benefiting the planet and cutting money. Actually, PHEVs are only slightly improved than regular gas and diesel cars in terms of energy consumption, CO₂ production, and operating expenses.”

Political Discussion and Automotive Lobbying

Hybrid vehicles have lately been brought back into policy debates as automakers have pressed the European Union to relax CO₂ standards. A proposed prohibition on new internal combustion cars in 2035 has faced heavy pressure from the automotive industry and opposition from member states with large car industries.

Several senior officials have proposed plug-in hybrids as a potential “flexibility” option to include in the regulation.

An independent energy policy specialist, who was unaffiliated with the research, described the report a “very useful contribution” after years in which parts of the car industry argued there was too little information to properly assess actual emissions.

“The results show, without question, that the gap between lab and real-world PHEV fuel consumption and CO₂ emissions is significantly greater than for petrol or diesel vehicles,” they stated. “All policy changes regarding PHEVs should be implemented with utmost care and considering this data.”