🔗 Share this article

Plug-in hybrid electric vehicles emit almost 5x greater global warming pollution than lab-reported figures show, according to a recent analysis.

Widening Discrepancy In Lab and Actual CO2 Output

Data reveals that PHEVs release just 19% less CO₂ than traditional petrol and diesel cars, based on research conducted by a advocacy group. This differs sharply with lab tests, which assumed a 75% reduction in emissions.

Researchers studied data from onboard fuel consumption monitors of eight hundred thousand vehicles registered in Europe between 2021 and 2023. They found that real-world CO₂ emissions from PHEVs in 2023 were nearly five times greater than official estimates, up from 3.5 times in 2021.

“Real-world emissions are increasing, while official figures are decreasing,” stated a lead researcher involved in the report. “This discrepancy is growing and poses a serious problem. As a result, PHEVs emit nearly as heavily as gasoline vehicles.”

Primary Factors Driving the Emissions Gap

Researchers attributed the majority of the gap to inflated estimates of the “utility factor” – the percentage of miles travelled in battery mode relative to overall distance. They determined that just a quarter of travel was done in electric mode, while lab assumptions assumed 84%.

Even, when operating in EV mode, emission levels were well above lab estimates. This occurred because electric motors were not strong enough to operate alone, leading to combustion motors burning gasoline for nearly a third of the travel completed in EV mode.

Policy and Economic Consequences

Based on calculations, the lowballing of PHEV emissions allowed four large automaker companies to avoid over €5bn in fines from 2021 and 2023, by falsely simplifying compliance with European Union average fleet CO₂ targets.

Furthermore, drivers of PHEVs would pay about €500 extra annually in operating costs than is assumed under lab conditions.

“The bold statements that manufacturers like to make about their PHEV cars are clearly way off the mark,” commented a automotive expert. “Consumers are being misled into believing that by buying a PHEV, they are benefiting the environment and cutting money. Actually, PHEVs are only slightly better than standard gas and diesel cars in terms of energy use, CO₂ emissions, and running expenses.”

Political Debate and Automotive Pressure

Plug-in hybrid cars have lately been brought again into political discussions as automakers have pressed the European Union to relax CO₂ targets. A proposed ban on sales of new internal combustion cars in 2035 has faced heavy pressure from the car industry and resistance from member states with significant automotive manufacturing.

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

An external energy economics expert, who was not involved with the research, called the report a “very useful contribution” after a long period in which segments of the car industry argued there was insufficient data to properly assess actual emissions.

“The results show, beyond any doubt, that the difference between official and actual PHEV energy use and CO₂ output is much, much greater than for gasoline or conventional vehicles,” they stated. “Any policy adjustments concerning PHEVs should be made with extreme caution and considering that data.”