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PHEVs release nearly five times more global warming emissions than official figures indicate, according to a recent analysis.

Widening Discrepancy Between Lab and Actual CO2 Output

Statistics shows that PHEVs release just one-fifth lower CO₂ than traditional petrol and diesel vehicles, according to research carried out by a advocacy organization. This differs sharply with lab tests, which suggested a 75% decrease in emissions.

Analysts studied information from onboard energy use meters of 800,000 vehicles registered in the EU from 2021 and 2023. The team discovered that actual CO₂ emissions from PHEVs in 2023 were 4.9 times higher than official figures, up from three and a half times in 2021.

“Real-world CO2 output are rising, while lab-reported emissions are falling,” said a lead analyst involved in the study. “This discrepancy is growing and poses a significant issue. As a result, PHEVs emit almost as heavily as petrol vehicles.”

Primary Factors Behind the Discrepancy

Analysts linked the majority of the difference to inflated estimates of the “utility factor” – the ratio of miles travelled in battery mode compared to total mileage. The team determined that just a quarter of driving was completed in EV mode, while lab estimates suggested 84%.

Additionally, when operating in electric mode, pollution levels were significantly higher than lab projections. This happened because EV motors were not strong sufficient to operate independently, leading to combustion motors burning gasoline for nearly one-third of the distance completed in EV mode.

Policy and Economic Implications

According to calculations, the underestimation of PHEV emissions allowed four large carmaker groups to avoid more than €5bn in fines from 2021 and 2023, by artificially simplifying adherence with European Union average fleet CO₂ standards.

Furthermore, owners of PHEVs could pay about €500 extra per year in operating costs than would be estimated under laboratory conditions.

“The bold claims that manufacturers like to make about their PHEV cars are clearly far from the mark,” stated a automotive analyst. “Consumers are being duped into believing that by buying a PHEV, they are benefiting the planet and saving costs. Actually, PHEVs are only slightly improved than regular gas and diesel cars in terms of energy use, CO₂ production, and running expenses.”

Policy Debate and Industry Pressure

Hybrid cars have lately been drawn back into political discussions as carmakers have lobbied the European Union to relax CO₂ targets. A planned prohibition on sales of new combustion engine vehicles in 2035 has faced intense pressure from the automotive industry and opposition from member states with significant car industries.

Some senior politicians have proposed PHEVs as a potential “flexibility” option to include in the regulation.

One independent energy policy expert, who was not involved with the study, described the report a “highly valuable contribution” after years in which parts of the automotive industry argued there was insufficient information to accurately evaluate actual emissions.

“The results show, beyond any doubt, that the difference in official and real-world PHEV fuel consumption and CO₂ output is much, much larger than for gasoline or conventional cars,” they said. “All regulatory adjustments regarding PHEVs should be implemented with extreme caution and in the light of this data.”