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PHEVs emit nearly 5x greater global warming emissions than lab-reported figures indicate, as per a recent report.

Growing Discrepancy Between Lab and Real-World CO2 Output

Statistics shows that PHEVs emit just one-fifth lower CO₂ than traditional gas and diesel vehicles, based on research carried out by a non-profit organization. That contrasts significantly with laboratory tests, which assumed a three-quarters decrease in emissions.

Analysts studied data from onboard energy use meters of 800,000 cars registered in Europe from 2021 and 2023. The team discovered that real-world CO₂ output from PHEVs in 2023 were nearly five times greater than official estimates, increased from three and a half times in 2021.

“Actual emissions are increasing, while lab-reported figures are falling,” said a lead analyst involved in the study. “That gap is growing and creates a significant issue. As a result, PHEVs pollute almost as much as gasoline vehicles.”

Key Reasons Behind the Discrepancy

Researchers linked the majority of the difference to overestimates of the “utility factor” – the ratio of kilometers driven in battery mode relative to overall mileage. The team determined that just 27% of travel was completed in EV mode, whereas official assumptions suggested over four-fifths.

Even, when running in EV mode, pollution amounts were significantly higher than official estimates. This happened because electric motors were not strong enough to operate independently, leading to engines burning fossil fuels for nearly a third of the distance covered in EV mode.

Regulatory and Economic Implications

According to estimates, the lowballing of PHEV emissions allowed four large automaker companies to escape more than €5bn in penalties from 2021 and 2023, by artificially simplifying compliance with EU average fleet CO₂ standards.

Furthermore, drivers of PHEVs would pay about €500 more per year in operating expenses than is estimated under lab conditions.

“The bold claims that automakers like to make about their plug-in hybrid cars are obviously far from the mark,” commented a transport analyst. “Buyers are being duped into thinking that by purchasing a PHEV, they are benefiting the environment and saving money. Actually, PHEVs are only slightly improved than regular petrol and diesel cars in terms of energy consumption, CO₂ emissions, and operating costs.”

Political Discussion and Industry Pressure

Hybrid cars have lately been drawn again into political debates as carmakers have pressed the EU to weaken CO₂ standards. A proposed prohibition on new internal combustion cars in 2035 has faced intense pressure from the car sector and resistance from EU countries with significant car manufacturing.

Some senior politicians have suggested PHEVs as a possible “flexibility” solution to introduce in the regulation.

An external energy policy expert, who was unaffiliated with the study, called the analysis a “highly valuable addition” after a long period in which parts of the car industry claimed there was insufficient information to accurately assess real-world CO2 output.

“These findings show, beyond any doubt, that the gap in official and actual PHEV fuel consumption and CO₂ emissions is much, much greater than for gasoline or diesel cars,” they stated. “All policy changes regarding PHEVs should be made with utmost care and in the light of that data.”