🔗 Share this article

Plug-in hybrid cars release almost 5x greater planet-heating emissions than official data indicate, as per a new report.

Widening Discrepancy In Lab and Real-World Emissions

Statistics reveals that PHEVs emit only one-fifth lower CO₂ than traditional petrol and diesel cars, according to research carried out by a advocacy organization. That contrasts significantly with laboratory estimates, which suggested a three-quarters reduction in pollution.

Analysts studied data from onboard fuel consumption monitors of eight hundred thousand vehicles registered in the EU between 2021 and 2023. They discovered that actual CO₂ emissions from PHEVs in 2023 were 4.9 times higher than official estimates, increased from three and a half times in 2021.

“Actual emissions are rising, while lab-reported figures are falling,” stated a lead analyst participating in the report. “This gap is growing and creates a significant issue. As a result, PHEVs emit almost as heavily as gasoline vehicles.”

Key Factors Behind the Discrepancy

Analysts linked the majority of the difference to inflated estimates of the “electric driving share” – the percentage of miles driven in battery mode relative to total distance. The team found that just a quarter of travel was completed in electric mode, whereas official estimates assumed over four-fifths.

Even, when running in EV mode, pollution amounts were well above lab projections. This occurred because EV motors were not strong sufficient to function independently, resulting to engines using gasoline for almost one-third of the distance covered in electric mode.

Policy and Economic Consequences

Based on calculations, the lowballing of PHEV emissions enabled four large carmaker groups to avoid over €5bn in fines between 2021 and 2023, by artificially easing adherence with European Union fleet-average CO₂ standards.

Furthermore, drivers of PHEVs would pay about €500 more per year in running expenses than is assumed under lab tests.

“The strong claims that manufacturers like to make about their plug-in hybrid vehicles are obviously far from the mark,” commented a transport analyst. “Consumers are being misled into believing that by purchasing a PHEV, they are benefiting the planet and saving money. Actually, PHEVs are little better than standard petrol and diesel cars in terms of energy consumption, CO₂ production, and running costs.”

Policy Discussion and Industry Lobbying

Plug-in hybrid cars have recently been brought back into political debates as carmakers have lobbied the European Union to weaken CO₂ targets. A proposed prohibition on sales of new internal combustion vehicles in 2035 has faced intense pressure from the car sector and opposition from member states with large automotive manufacturing.

Several high-level officials have proposed PHEVs as a potential “compromise” solution to introduce in the regulation.

One independent energy policy expert, who was unaffiliated with the research, described the report a “very useful addition” after years in which segments of the car sector argued there was insufficient information to properly assess real-world CO2 output.

“The results show, without question, that the gap between lab and real-world PHEV fuel consumption and CO₂ emissions is much, much greater than for petrol or diesel vehicles,” the expert said. “Any policy adjustments regarding PHEVs should be made with extreme caution and in the light of this data.”