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PHEVs release nearly five times more global warming pollution than official figures show, as per a recent analysis.

Growing Discrepancy Between Lab and Actual CO2 Output

Data shows that PHEVs emit just 19% less CO₂ than traditional petrol and diesel cars, based on research carried out by a non-profit organization. This contrasts sharply with lab tests, which suggested a 75% decrease in pollution.

Analysts studied data from onboard energy use meters of 800,000 vehicles sold in Europe from 2021 and 2023. The team found that actual CO₂ emissions from PHEVs in 2023 were nearly five times greater than official estimates, up from three and a half times in 2021.

“Real-world CO2 output are increasing, while official figures are decreasing,” said a lead researcher participating in the report. “That gap is widening and creates a serious problem. As a result, PHEVs pollute almost as heavily as petrol vehicles.”

Key Factors Driving the Discrepancy

Analysts linked most of the gap to inflated estimates of the “electric driving share” – the ratio of miles driven in battery power relative to overall mileage. The team determined that only 27% of travel was done in EV mode, while lab assumptions assumed over four-fifths.

Even, when operating in electric mode, emission levels were well above official estimates. This occurred because electric motors were insufficiently powerful sufficient to function alone, leading to engines using gasoline for almost one-third of the travel completed in EV mode.

Regulatory and Economic Consequences

Based on calculations, the underestimation of PHEV emissions enabled several large carmaker companies to escape over €5bn in penalties from 2021 and 2023, by falsely easing compliance with EU fleet-average CO₂ standards.

Furthermore, drivers of PHEVs could spend about €500 more per year in operating costs than is assumed under laboratory tests.

“The bold claims that automakers like to make about their PHEV vehicles are clearly way off the mark,” stated a automotive expert. “Consumers are being misled into thinking that by buying a PHEV, they are helping the planet and saving costs. Actually, PHEVs are only slightly better than standard gas and diesel cars in terms of energy use, CO₂ production, and running expenses.”

Policy Debate and Industry Pressure

Plug-in hybrid vehicles have lately been drawn again into political debates as carmakers have pressed the EU to relax CO₂ targets. A proposed ban on new combustion engine cars in 2035 has faced intense lobbying from the automotive sector and resistance from EU countries with significant automotive industries.

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

One independent energy policy expert, who was unaffiliated with the research, described the report a “very useful addition” after years in which parts 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 between official and actual PHEV energy use and CO₂ output is much, much greater than for gasoline or diesel cars,” they stated. “All policy changes regarding PHEVs should be made with extreme care and considering that evidence.”