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PHEVs produce nearly five times more planet-heating emissions than lab-reported data show, as per a recent analysis.

Growing Discrepancy Between Official and Actual Emissions

Data reveals that PHEVs emit just 19% lower CO₂ than traditional petrol and diesel cars, according to analysis carried out by a advocacy organization. This differs significantly with lab tests, which assumed a 75% reduction in emissions.

Researchers examined data from onboard energy use meters of 800,000 cars sold in Europe between 2021 and 2023. The team discovered that real-world CO₂ emissions from PHEVs in 2023 were 4.9 times greater than lab estimates, increased from 3.5 times in 2021.

“Actual emissions are increasing, while official emissions are falling,” stated a lead analyst involved in the report. “That gap is widening and poses a serious problem. As a result, PHEVs emit nearly as much as petrol cars.”

Key Factors Driving the Discrepancy

Analysts linked the majority of the gap to overestimates of the “electric driving share” – the percentage of miles travelled in battery mode compared to total distance. The team found that just a quarter of travel was done in EV mode, while official estimates suggested 84%.

Even, when running in electric mode, emission amounts were significantly higher than official estimates. That occurred because EV motors were not strong enough to operate alone, leading to engines burning fossil fuels for almost a third of the distance completed in electric mode.

Regulatory and Financial Consequences

Based on calculations, the lowballing of PHEV emissions enabled four large automaker groups to avoid more than €5bn in fines from 2021 and 2023, by falsely simplifying adherence with EU fleet-average CO₂ targets.

Additionally, owners of PHEVs would pay approximately €500 extra per year in running expenses than would be assumed under lab conditions.

“The strong claims that automakers like to make about their plug-in hybrid vehicles are clearly far from the mark,” stated a automotive analyst. “Consumers are being misled into believing that by purchasing a PHEV, they are benefiting the planet and cutting costs. Actually, PHEVs are little improved than standard petrol and diesel vehicles in terms of energy use, CO₂ emissions, and operating expenses.”

Policy Debate and Automotive Pressure

Hybrid cars have recently been drawn again into political discussions as automakers have lobbied the EU to weaken CO₂ standards. A planned ban on sales of new internal combustion cars in 2035 has faced intense lobbying from the car industry and opposition from EU countries with significant automotive industries.

Some senior officials have proposed plug-in hybrids as a potential “compromise” option to introduce in the regulation.

One independent energy policy specialist, who was not involved with the study, called the report a “very useful contribution” after years in which parts of the automotive industry argued there was too little data to properly assess real-world emissions.

“The results show, beyond any doubt, that the difference in official and real-world PHEV energy use and CO₂ emissions is significantly larger than for gasoline or diesel vehicles,” they stated. “Any policy changes regarding PHEVs should be made with utmost caution and considering this evidence.”