🔗 Share this article

Plug-in hybrid electric vehicles release nearly five times more global warming pollution than lab-reported figures indicate, as per a recent analysis.

Widening Gap Between Lab and Actual Emissions

Statistics shows that PHEVs release just one-fifth less CO₂ than traditional petrol and diesel vehicles, based on analysis carried out by a non-profit organization. This differs significantly with laboratory tests, which suggested a three-quarters decrease in emissions.

Analysts studied data from in-vehicle fuel consumption meters of 800,000 vehicles sold in Europe from 2021 and 2023. The team found that real-world CO₂ emissions from PHEVs in 2023 were 4.9 times higher than lab estimates, increased from 3.5 times in 2021.

“Actual CO2 output are increasing, while lab-reported figures are falling,” said a lead analyst involved in the report. “This discrepancy is widening and creates a serious problem. As a result, PHEVs emit almost as heavily as petrol vehicles.”

Key Reasons Driving the Emissions Gap

Analysts attributed the majority of the difference to inflated estimates of the “utility factor” – the ratio of kilometers travelled in battery power relative to total distance. They determined that only 27% of travel was done in EV mode, whereas official assumptions suggested 84%.

Even, when running in EV mode, pollution levels were well above lab estimates. That happened because electric motors were not strong enough to function independently, resulting to engines burning gasoline for almost a third of the travel completed in EV mode.

Policy and Economic Implications

Based on calculations, the lowballing of PHEV emissions enabled several large automaker companies to avoid over €5bn in penalties from 2021 and 2023, by falsely simplifying compliance with EU average fleet CO₂ targets.

Additionally, drivers of PHEVs could spend approximately €500 more per year in running expenses than would be estimated under lab conditions.

“The bold statements that automakers like to make about their PHEV vehicles are obviously far from the mark,” stated a transport expert. “Buyers are being misled into believing that by buying a PHEV, they are helping the environment and cutting costs. Actually, PHEVs are little better than standard petrol and diesel vehicles in terms of fuel use, CO₂ emissions, and operating expenses.”

Policy Discussion and Industry Lobbying

Plug-in hybrid cars have recently been brought back into political discussions as carmakers have lobbied the EU to relax CO₂ standards. A planned ban on new internal combustion vehicles in 2035 has faced heavy pressure from the car industry and resistance from member states with significant automotive manufacturing.

Several senior politicians have suggested plug-in hybrids as a potential “flexibility” solution to introduce in the regulation.

One external energy economics specialist, who was unaffiliated with the study, called the report a “highly valuable contribution” after years in which segments of the automotive industry claimed there was too little data to accurately assess real-world emissions.

“These findings demonstrate, without question, that the difference in lab and real-world PHEV energy use and CO₂ output is much, much larger than for petrol or conventional vehicles,” the expert stated. “All policy adjustments regarding PHEVs should be made with utmost care and considering this evidence.”