🔗 Share this article

PHEVs produce nearly five times more planet-heating emissions than official data show, as per a new analysis.

Growing Gap Between Lab and Actual Emissions

Data shows that PHEVs release only 19% lower CO₂ than conventional petrol and diesel cars, according to research carried out by a advocacy organization. That contrasts significantly with laboratory estimates, which assumed a 75% reduction in pollution.

Researchers examined data from in-vehicle fuel consumption monitors of eight hundred thousand vehicles sold in the EU between 2021 and 2023. They found that real-world CO₂ output from PHEVs in 2023 were nearly five times higher than lab estimates, up from 3.5 times in 2021.

“Actual CO2 output are rising, while official emissions are falling,” said a lead researcher involved in the report. “This discrepancy is growing and poses a serious issue. Consequently, PHEVs emit nearly as much as petrol vehicles.”

Primary Factors Behind the Emissions Gap

Researchers attributed most of the gap to inflated estimates of the “utility factor” – the ratio of kilometers travelled in battery power compared to overall distance. The team determined that just a quarter of driving was done in EV mode, while official estimates suggested 84%.

Even, when running in EV mode, emission levels were significantly higher than official projections. That happened because electric motors were not strong sufficient to operate independently, resulting to engines burning gasoline for almost a third of the travel covered in electric mode.

Regulatory and Economic Consequences

Based on estimates, the lowballing of PHEV emissions allowed several large automaker groups to avoid over €5bn in fines between 2021 and 2023, by artificially simplifying adherence with European Union fleet-average CO₂ standards.

Additionally, drivers of PHEVs could pay approximately €500 extra annually in running costs than would be estimated under laboratory conditions.

“The bold statements that automakers like to make about their PHEV vehicles are clearly far from the mark,” stated a automotive analyst. “Buyers are being duped into thinking that by buying a PHEV, they are helping the planet and saving costs. Actually, PHEVs are only slightly improved than regular petrol and diesel cars in terms of fuel use, CO₂ production, and operating expenses.”

Policy Discussion and Industry Lobbying

Hybrid cars have lately been drawn again into policy debates as carmakers have lobbied the European Union to relax CO₂ targets. A planned prohibition on new combustion engine cars in 2035 has faced heavy lobbying from the car sector and opposition from member states with significant car manufacturing.

Some senior politicians have proposed plug-in hybrids as a possible “compromise” option to include in the legislation.

An external energy policy expert, who was not involved with the research, called the analysis a “very useful contribution” after a long period in which parts of the car industry argued there was insufficient information to properly evaluate actual CO2 output.

“These findings show, without question, that the gap in lab and real-world PHEV energy use and CO₂ emissions is significantly greater than for gasoline or diesel vehicles,” the expert said. “Any regulatory adjustments regarding PHEVs should be implemented with utmost caution and in the light of that evidence.”