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PHEVs release nearly 5x more global warming pollution than official data indicate, as per a recent analysis.

Growing Gap In Official and Actual CO2 Output

Statistics reveals that PHEVs release only 19% lower CO₂ than traditional gas and diesel cars, according to research conducted by a advocacy organization. This differs significantly with laboratory estimates, which assumed a three-quarters decrease in pollution.

Analysts examined data from onboard energy use monitors of 800,000 vehicles sold in the EU from 2021 and 2023. They found that real-world CO₂ output from PHEVs in 2023 were nearly five times higher than official figures, up from three and a half times in 2021.

“Real-world CO2 output are rising, while official figures are falling,” said a lead analyst participating in the report. “This gap is growing and poses a significant issue. As a result, PHEVs pollute almost as heavily as gasoline vehicles.”

Key Reasons Behind the Emissions Gap

Analysts attributed the majority of the difference to overestimates of the “utility factor” – the ratio of kilometers driven in battery mode compared to overall mileage. They found that only 27% of driving was completed in electric mode, whereas lab estimates suggested 84%.

Even, when operating in EV mode, emission levels were significantly higher than official estimates. That happened because EV motors were insufficiently powerful sufficient to operate alone, resulting to engines burning gasoline for nearly one-third of the travel completed in electric mode.

Policy and Financial Consequences

Based on estimates, the lowballing of PHEV CO2 output allowed several large automaker groups to avoid over €5bn in fines between 2021 and 2023, by artificially simplifying compliance with EU fleet-average CO₂ standards.

Furthermore, owners of PHEVs would spend approximately €500 more per year in running costs than is assumed under lab conditions.

“The strong statements that manufacturers like to make about their plug-in hybrid vehicles are clearly far from the mark,” commented a transport expert. “Consumers are being misled into thinking that by purchasing a PHEV, they are helping the environment and saving money. Actually, PHEVs are only slightly better than standard gas and diesel cars in terms of energy consumption, CO₂ production, and operating expenses.”

Political Discussion and Industry Pressure

Hybrid vehicles have recently been drawn back into policy debates as automakers have lobbied the European Union to relax CO₂ standards. A proposed ban on sales of new internal combustion cars in 2035 has faced intense lobbying from the car industry and opposition from member states with large automotive industries.

Some senior politicians have proposed plug-in hybrids as a potential “flexibility” solution to include in the legislation.

One independent energy economics specialist, who was not involved with the research, called the report a “very useful addition” after years in which segments of the automotive sector argued there was insufficient data to accurately assess real-world emissions.

“These findings show, without question, that the gap between lab and real-world PHEV fuel consumption and CO₂ emissions is significantly greater than for petrol or diesel cars,” the expert stated. “Any regulatory changes regarding PHEVs should be implemented with utmost care and in the light of that evidence.”