🔗 Share this article

Plug-in hybrid cars produce nearly five times greater global warming pollution than lab-reported figures indicate, as per a new report.

Growing Discrepancy In Official and Real-World Emissions

Data shows that PHEVs release just one-fifth less CO₂ than traditional gas and diesel cars, according to analysis carried out by a non-profit organization. That contrasts sharply with laboratory estimates, which suggested a 75% decrease in emissions.

Researchers examined information from onboard fuel consumption monitors of eight hundred thousand cars sold in the EU from 2021 and 2023. They discovered that actual CO₂ emissions from PHEVs in 2023 were 4.9 times greater than lab estimates, up from three and a half times in 2021.

“Actual emissions are increasing, while lab-reported emissions are falling,” said a senior analyst involved in the report. “That gap is growing and poses a significant issue. Consequently, PHEVs emit almost as heavily as petrol vehicles.”

Key Reasons Behind the Discrepancy

Analysts linked the majority of the difference to inflated estimates of the “electric driving share” – the percentage of miles travelled in battery power compared to overall mileage. The team determined that just 27% of driving was completed in EV mode, while official assumptions assumed over four-fifths.

Even, when running in electric mode, pollution levels were well above official estimates. That happened because electric motors were insufficiently powerful sufficient to function alone, leading to combustion motors burning gasoline for nearly one-third of the travel covered in EV mode.

Policy and Economic Implications

According to 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 adherence with European Union fleet-average CO₂ standards.

Furthermore, drivers of PHEVs could pay approximately €500 extra per year in running expenses than is assumed under laboratory tests.

“The strong claims that manufacturers like to make about their plug-in hybrid vehicles are obviously far from the mark,” stated a automotive analyst. “Buyers are being duped into believing that by buying a PHEV, they are benefiting the environment and cutting costs. In reality, PHEVs are only slightly better than regular gas and diesel cars in terms of fuel use, CO₂ production, and running costs.”

Policy Debate and Industry Lobbying

Hybrid cars have lately been drawn back into policy discussions as carmakers have pressed the European Union to relax CO₂ targets. A proposed ban on sales of new combustion engine cars in 2035 has faced intense pressure from the automotive sector and opposition from EU countries with significant car manufacturing.

Some senior politicians have suggested plug-in hybrids as a potential “compromise” option to introduce in the legislation.

One external energy policy specialist, who was unaffiliated with the study, called the report a “very useful addition” after years in which parts of the automotive sector claimed there was insufficient data to accurately evaluate real-world emissions.

“These findings demonstrate, beyond any doubt, that the difference in official and real-world PHEV energy use and CO₂ emissions is significantly larger than for petrol or conventional cars,” the expert stated. “Any regulatory changes concerning PHEVs should be implemented with utmost caution and in the light of that evidence.”