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PHEVs release almost 5x greater planet-heating emissions than lab-reported data show, as per a recent analysis.

Widening Gap In Lab and Real-World Emissions

Statistics shows that PHEVs release only one-fifth lower CO₂ than traditional gas and diesel vehicles, according to analysis carried out by a non-profit organization. This contrasts sharply with lab estimates, which assumed a three-quarters decrease in pollution.

Analysts examined data from in-vehicle energy use monitors of eight hundred thousand vehicles sold in the EU between 2021 and 2023. The team found that actual CO₂ emissions from PHEVs in 2023 were nearly five times higher than official estimates, up from 3.5 times in 2021.

“Real-world emissions are increasing, while official figures are decreasing,” stated a lead analyst involved in the study. “That discrepancy is widening and creates a serious problem. Consequently, PHEVs emit almost as heavily as petrol cars.”

Key Factors Driving the Discrepancy

Researchers linked most of the gap to inflated estimates of the “electric driving share” – the percentage of miles driven in battery power compared to overall distance. They found that just 27% of driving was completed in electric mode, while lab estimates assumed 84%.

Additionally, when running in EV mode, emission levels were significantly higher than official estimates. This happened because EV motors were insufficiently powerful sufficient to function alone, resulting to engines burning gasoline for almost one-third of the distance completed in EV mode.

Regulatory and Economic Implications

Based on calculations, the underestimation of PHEV CO2 output enabled four major automaker companies to escape more than €5bn in penalties between 2021 and 2023, by artificially simplifying compliance with EU average fleet CO₂ targets.

Additionally, drivers of PHEVs would pay approximately €500 extra per year in running expenses than would be assumed under laboratory conditions.

“The strong claims that manufacturers like to make about their plug-in hybrid vehicles are clearly way off the truth,” commented a transport expert. “Consumers are being duped into believing that by purchasing a PHEV, they are benefiting the planet and cutting money. Actually, PHEVs are little better than regular petrol and diesel vehicles in terms of energy consumption, CO₂ production, and operating costs.”

Political Discussion and Automotive Pressure

Plug-in hybrid cars have recently been brought again into policy debates as carmakers have lobbied the European Union to relax CO₂ standards. A planned prohibition on sales of new internal combustion vehicles in 2035 has faced heavy lobbying from the automotive industry and opposition from EU countries with large car industries.

Some high-level politicians have proposed plug-in hybrids as a possible “flexibility” option to introduce in the regulation.

One external energy economics specialist, who was unaffiliated with the research, called the report a “highly valuable addition” after a long period in which parts of the automotive sector argued there was too little information to properly assess real-world CO2 output.

“These findings show, beyond any doubt, that the gap in official and actual PHEV energy use and CO₂ emissions is significantly greater than for petrol or conventional vehicles,” they stated. “Any regulatory changes regarding PHEVs should be made with extreme caution and in the light of that evidence.”