🔗 Share this article

Plug-in hybrid cars release almost 5x more global warming emissions than official figures show, as per a new analysis.

Widening Discrepancy In Official and Actual Emissions

Data reveals that PHEVs release just one-fifth less CO₂ than conventional petrol and diesel vehicles, based on research carried out by a advocacy organization. This contrasts sharply with lab estimates, which suggested a three-quarters decrease in pollution.

Researchers examined data from onboard energy use monitors of 800,000 vehicles registered in Europe from 2021 and 2023. They found that actual CO₂ emissions from PHEVs in 2023 were 4.9 times greater than official figures, up from 3.5 times in 2021.

“Actual CO2 output are rising, while official figures are falling,” stated a senior analyst participating in the report. “This discrepancy is growing and creates a serious issue. Consequently, PHEVs pollute nearly as much as petrol cars.”

Key Reasons Driving the Discrepancy

Analysts linked most of the difference to inflated estimates of the “electric driving share” – the percentage of miles travelled in battery power compared to total distance. The team determined that just a quarter of travel was done in electric mode, whereas lab estimates assumed 84%.

Even, when operating in EV mode, emission amounts were significantly higher than lab projections. This happened because EV motors were not strong sufficient to function alone, leading to engines using gasoline for nearly a third of the travel completed in EV mode.

Policy and Economic Implications

Based on estimates, the lowballing of PHEV emissions allowed several major carmaker companies to escape over €5bn in fines between 2021 and 2023, by falsely simplifying compliance with European Union average fleet CO₂ targets.

Furthermore, drivers of PHEVs would pay approximately €500 more annually in operating costs than would be assumed under laboratory conditions.

“The strong statements that automakers often promote about their plug-in hybrid vehicles are clearly far from the truth,” commented a automotive expert. “Buyers are being misled into believing that by buying a PHEV, they are benefiting the planet and saving costs. Actually, PHEVs are only slightly improved than standard petrol and diesel vehicles in terms of fuel consumption, CO₂ emissions, and running costs.”

Political Debate and Industry Pressure

Hybrid cars have recently been brought again into policy discussions as automakers have lobbied the European Union to weaken CO₂ targets. A proposed ban on sales of new combustion engine vehicles in 2035 has faced heavy lobbying from the automotive sector and opposition from EU countries with large automotive industries.

Some senior officials have proposed PHEVs as a potential “flexibility” option to include in the regulation.

One independent energy policy expert, who was unaffiliated with the research, called the analysis a “highly valuable contribution” after a long period in which segments of the automotive sector argued there was insufficient data to accurately evaluate actual emissions.

“These findings show, beyond any doubt, that the difference in lab and actual PHEV fuel consumption and CO₂ emissions is significantly larger than for gasoline or diesel cars,” the expert said. “All policy adjustments concerning PHEVs should be implemented with extreme care and in the light of that data.”