🔗 Share this article

Plug-in hybrid cars release nearly five times greater planet-heating pollution than official figures show, as per a new report.

Growing Gap In Official and Real-World Emissions

Statistics shows that PHEVs emit just 19% lower CO₂ than conventional petrol and diesel cars, based on analysis carried out by a non-profit group. This differs significantly with lab estimates, which suggested a three-quarters decrease in pollution.

Analysts examined information from in-vehicle fuel consumption meters of eight hundred thousand vehicles sold in Europe from 2021 and 2023. They discovered that actual CO₂ output from PHEVs in 2023 were 4.9 times greater than lab estimates, up from 3.5 times in 2021.

“Real-world CO2 output are increasing, while lab-reported figures are decreasing,” stated a lead analyst participating in the study. “This discrepancy is widening and creates a significant problem. As a result, PHEVs pollute nearly as much as petrol vehicles.”

Key Reasons Behind the Discrepancy

Analysts linked most of the difference to overestimates of the “electric driving share” – the percentage of kilometers travelled in electric power compared to total distance. They found that only a quarter of travel was done in EV mode, while lab assumptions assumed over four-fifths.

Additionally, when operating in electric mode, emission amounts were significantly higher than lab estimates. That happened because electric motors were not strong enough to function alone, resulting to combustion motors burning fossil fuels for almost one-third of the distance completed in electric mode.

Regulatory and Financial Implications

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

Additionally, drivers of PHEVs would spend approximately €500 more per year in operating expenses than would be estimated under laboratory tests.

“The strong claims that manufacturers like to make about their plug-in hybrid cars are clearly far from the mark,” stated a automotive expert. “Consumers are being misled into thinking that by buying a PHEV, they are helping the planet and cutting money. Actually, PHEVs are only slightly better than standard gas and diesel cars in terms of fuel use, CO₂ emissions, and running expenses.”

Political Discussion and Automotive Lobbying

Hybrid cars have lately been brought again into political discussions as carmakers have lobbied the EU to weaken CO₂ targets. A proposed ban on sales of new combustion engine cars in 2035 has faced heavy pressure from the car sector and opposition from member states with significant automotive manufacturing.

Several senior officials have suggested plug-in hybrids as a possible “flexibility” option to include in the legislation.

One external energy economics specialist, who was not involved with the research, described the analysis a “highly valuable contribution” after years in which parts of the car industry claimed there was too little information to properly assess real-world emissions.

“These findings show, without question, that the difference in official and actual PHEV energy use and CO₂ emissions is significantly larger than for petrol or conventional cars,” they said. “Any policy adjustments concerning PHEVs should be made with utmost caution and in the light of that evidence.”