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PHEVs emit almost five times greater planet-heating emissions than official figures show, as per a recent report.

Growing Discrepancy In Official and Real-World Emissions

Statistics shows that PHEVs release just one-fifth lower CO₂ than conventional petrol and diesel vehicles, based on analysis conducted by a advocacy organization. That differs significantly with laboratory estimates, which assumed a three-quarters reduction in emissions.

Researchers examined information from in-vehicle fuel consumption monitors of 800,000 cars registered in the EU between 2021 and 2023. They discovered that real-world CO₂ emissions from PHEVs in 2023 were 4.9 times greater than official figures, increased from 3.5 times in 2021.

“Actual emissions are rising, while lab-reported emissions are falling,” stated a lead researcher involved in the report. “That discrepancy is widening and poses a significant issue. As a result, PHEVs pollute nearly as much as petrol cars.”

Key Reasons Behind the Discrepancy

Researchers linked the majority of the difference to inflated estimates of the “utility factor” – the ratio of miles driven in electric power compared to overall mileage. The team determined that only 27% of travel was done in EV mode, while lab estimates assumed over four-fifths.

Even, when operating in EV mode, emission levels were well above official estimates. That occurred because electric motors were insufficiently powerful sufficient to operate alone, leading to combustion motors burning gasoline for nearly a third of the travel covered in EV mode.

Regulatory and Economic Implications

Based on calculations, the underestimation of PHEV CO2 output enabled several large automaker groups to escape over €5bn in fines from 2021 and 2023, by artificially simplifying compliance with European Union fleet-average CO₂ standards.

Furthermore, drivers of PHEVs would spend approximately €500 extra per year in running costs than is assumed under lab tests.

“The strong statements that automakers like to make about their PHEV cars are obviously far from the mark,” stated a transport analyst. “Buyers are being misled into believing that by buying a PHEV, they are benefiting the planet and cutting costs. Actually, PHEVs are only slightly improved than standard gas and diesel vehicles in terms of fuel use, CO₂ emissions, and running costs.”

Policy Discussion and Automotive Lobbying

Hybrid cars have lately been brought back into policy debates as carmakers have lobbied the European Union to weaken CO₂ targets. A proposed ban on sales of new combustion engine cars in 2035 has faced heavy pressure from the car industry and opposition from EU countries with large automotive industries.

Some high-level politicians have suggested plug-in hybrids as a possible “compromise” solution to include in the legislation.

One independent energy policy expert, who was not involved with the study, called the report a “very useful addition” after a long period in which segments of the automotive sector claimed there was too little data to properly evaluate actual emissions.

“These findings show, beyond any doubt, that the difference between official and actual PHEV fuel consumption and CO₂ emissions is significantly greater than for petrol or conventional cars,” they stated. “Any policy adjustments concerning PHEVs should be made with extreme care and in the light of this evidence.”