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Plug-in hybrid cars release nearly 5x more planet-heating pollution than lab-reported figures indicate, as per a recent analysis.

Widening Discrepancy In Official and Real-World CO2 Output

Statistics shows that PHEVs emit just one-fifth less CO₂ than conventional gas and diesel vehicles, according to research carried out by a advocacy organization. This differs sharply with lab estimates, which assumed a 75% reduction in emissions.

Researchers studied information from in-vehicle fuel consumption monitors of eight hundred thousand cars registered in Europe from 2021 and 2023. The team found that real-world CO₂ output from PHEVs in 2023 were nearly five times higher than official estimates, increased from 3.5 times in 2021.

“Actual CO2 output are increasing, while official figures are falling,” said a senior analyst involved in the study. “This discrepancy is widening and creates a significant issue. Consequently, PHEVs emit almost as much as petrol cars.”

Primary Factors Behind the Discrepancy

Researchers attributed the majority of the gap to overestimates of the “utility factor” – the ratio of miles driven in battery power compared to overall mileage. They found that just a quarter of travel was done in EV mode, whereas official estimates assumed 84%.

Even, when operating in electric mode, pollution amounts were significantly higher than lab estimates. That occurred because EV motors were insufficiently powerful sufficient to operate independently, leading to engines using gasoline for nearly one-third of the distance covered in EV mode.

Policy and Economic Consequences

Based on estimates, the lowballing of PHEV CO2 output enabled four major automaker companies to avoid over €5bn in penalties from 2021 and 2023, by artificially easing compliance with European Union average fleet CO₂ standards.

Furthermore, drivers of PHEVs would spend about €500 more annually in running expenses than is assumed under lab conditions.

“The bold claims that automakers like to make about their plug-in hybrid cars are clearly far from the mark,” stated a automotive expert. “Buyers are being duped into believing that by purchasing a PHEV, they are helping the environment and cutting money. In reality, PHEVs are only slightly improved than regular gas and diesel vehicles in terms of fuel consumption, CO₂ emissions, and running expenses.”

Policy Debate and Automotive Pressure

Plug-in hybrid cars have lately been drawn back into policy discussions as carmakers have lobbied the European Union to weaken CO₂ standards. A planned ban on sales of new internal combustion cars in 2035 has faced heavy pressure from the automotive sector and opposition from member states with large automotive industries.

Some high-level officials have suggested plug-in hybrids as a possible “compromise” option to introduce in the regulation.

An independent energy policy specialist, who was not involved with the study, called the report a “very useful addition” after years in which segments of the automotive sector claimed there was insufficient data to accurately evaluate actual CO2 output.

“These findings demonstrate, beyond any doubt, that the difference in official and actual PHEV energy use and CO₂ output is significantly larger than for gasoline or diesel vehicles,” the expert stated. “All policy adjustments concerning PHEVs should be made with extreme caution and in the light of this data.”