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PHEVs produce nearly 5x greater planet-heating pollution than official figures show, as per a recent analysis.

Growing Gap Between Lab and Actual Emissions

Statistics reveals that PHEVs release just one-fifth less CO₂ than traditional gas and diesel vehicles, based on analysis conducted by a non-profit group. This differs significantly with lab tests, which assumed a three-quarters decrease in emissions.

Analysts examined data from in-vehicle energy use monitors of eight hundred thousand vehicles sold 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, increased from three and a half times in 2021.

“Real-world emissions are increasing, while lab-reported emissions are falling,” said a senior analyst participating in the study. “This gap is widening and poses a serious issue. As a result, PHEVs emit nearly as much as gasoline cars.”

Key Reasons Behind the Discrepancy

Researchers linked most of the difference to overestimates of the “utility factor” – the percentage of miles driven in battery power compared to overall mileage. They found that only 27% of driving was done in EV mode, whereas official estimates assumed 84%.

Additionally, when running in electric mode, emission amounts were significantly higher than lab projections. That occurred because EV motors were insufficiently powerful enough to function alone, resulting to engines burning fossil fuels for almost one-third of the distance completed in electric mode.

Regulatory and Financial Consequences

Based on calculations, the lowballing of PHEV CO2 output allowed several major automaker companies to avoid more than €5bn in fines from 2021 and 2023, by artificially simplifying adherence with EU fleet-average CO₂ targets.

Additionally, owners of PHEVs would pay approximately €500 extra annually in operating costs than would be assumed under lab tests.

“The strong claims that automakers like to make about their plug-in hybrid cars are obviously way off the mark,” stated a automotive expert. “Consumers are being misled into believing that by purchasing a PHEV, they are benefiting the environment and saving costs. Actually, PHEVs are little better than regular gas and diesel vehicles in terms of fuel consumption, CO₂ emissions, and operating expenses.”

Policy Debate and Industry Pressure

Plug-in hybrid cars have lately been brought back into political debates as automakers have pressed the EU to weaken CO₂ standards. A proposed ban on sales of new internal combustion vehicles in 2035 has faced heavy pressure from the car sector and opposition from EU countries with large car manufacturing.

Several high-level officials have suggested plug-in hybrids as a possible “compromise” option to include in the legislation.

An independent energy policy expert, who was unaffiliated with the research, called the analysis a “very useful contribution” after a long period in which segments of the automotive industry argued there was insufficient information to properly evaluate actual emissions.

“The results demonstrate, beyond any doubt, that the difference between official and actual PHEV fuel consumption and CO₂ emissions is significantly greater than for gasoline or diesel vehicles,” the expert stated. “Any regulatory changes concerning PHEVs should be made with utmost caution and considering this evidence.”