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PHEVs produce nearly 5x more global warming pollution than lab-reported figures show, as per a recent analysis.

Growing Discrepancy Between Lab and Real-World Emissions

Statistics shows that PHEVs emit just 19% less CO₂ than traditional gas and diesel vehicles, based on analysis conducted by a non-profit group. This differs sharply with laboratory tests, which suggested a three-quarters decrease in emissions.

Researchers studied information from in-vehicle energy use monitors of eight hundred thousand vehicles sold in the EU from 2021 and 2023. They found that real-world CO₂ emissions from PHEVs in 2023 were 4.9 times higher than official estimates, increased from three and a half times in 2021.

“Actual CO2 output are increasing, while official figures are falling,” stated a senior researcher participating in the report. “This gap is growing and poses a serious issue. Consequently, PHEVs emit nearly as much as petrol vehicles.”

Key Factors Behind the Discrepancy

Researchers linked the majority of the difference to inflated estimates of the “utility factor” – the percentage of miles travelled in battery power compared to total distance. The team found that only a quarter of driving was completed in electric mode, while official estimates suggested over four-fifths.

Additionally, when running in electric mode, emission amounts were well above official projections. That occurred because electric motors were not strong enough to operate independently, resulting to combustion motors using gasoline for almost one-third of the travel completed in electric mode.

Policy and Financial Consequences

According to calculations, the lowballing of PHEV CO2 output allowed several large carmaker groups to avoid more than €5bn in fines from 2021 and 2023, by artificially easing compliance with EU average fleet CO₂ standards.

Furthermore, owners of PHEVs would pay approximately €500 extra annually in running costs than would be estimated under lab tests.

“The strong statements that automakers often promote about their PHEV cars are clearly far from the mark,” stated a automotive analyst. “Consumers are being misled into thinking that by purchasing a PHEV, they are benefiting the planet and cutting money. In reality, PHEVs are little improved than regular petrol and diesel cars in terms of energy use, CO₂ emissions, and operating costs.”

Political Discussion and Industry Lobbying

Hybrid vehicles have lately been brought back into political discussions as carmakers have pressed the EU to weaken CO₂ targets. A planned prohibition on sales of new internal combustion vehicles in 2035 has faced intense lobbying from the car sector and opposition from EU countries with significant car industries.

Some senior officials have suggested plug-in hybrids as a possible “compromise” solution to introduce in the regulation.

One independent energy policy expert, who was not involved with the study, described the analysis a “highly valuable addition” after years in which segments of the car sector argued there was too little information to properly evaluate real-world CO2 output.

“These findings show, beyond any doubt, 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 said. “Any regulatory adjustments regarding PHEVs should be implemented with extreme caution and considering that data.”