🔗 Share this article

Plug-in hybrid electric vehicles produce nearly five times more global warming pollution than official figures indicate, as per a new report.

Growing Discrepancy Between Lab and Real-World CO2 Output

Statistics reveals that PHEVs release only one-fifth lower CO₂ than traditional petrol and diesel vehicles, based on analysis conducted by a advocacy group. This contrasts significantly with lab tests, which assumed a 75% decrease in pollution.

Analysts studied data from in-vehicle fuel consumption monitors of eight hundred thousand vehicles registered in the EU from 2021 and 2023. The team discovered that real-world CO₂ emissions from PHEVs in 2023 were 4.9 times higher than official figures, increased from 3.5 times in 2021.

“Real-world CO2 output are rising, while lab-reported figures are decreasing,” said a lead researcher participating in the report. “This gap is widening and poses a serious issue. Consequently, PHEVs emit almost as much as petrol cars.”

Key Reasons Driving the Discrepancy

Researchers attributed the majority of the difference to inflated estimates of the “utility factor” – the ratio of kilometers driven in battery mode relative to overall mileage. The team determined that only 27% of travel was completed in EV mode, while official estimates suggested over four-fifths.

Even, when running in electric mode, pollution levels were well above lab estimates. This happened because EV motors were not strong enough to operate independently, leading to engines burning fossil fuels for nearly one-third of the travel completed in EV mode.

Policy and Financial Implications

According to estimates, the underestimation of PHEV emissions allowed several large automaker companies to avoid over €5bn in fines from 2021 and 2023, by falsely simplifying compliance with EU fleet-average CO₂ standards.

Additionally, drivers of PHEVs would pay about €500 more annually in running costs than is assumed under lab tests.

“The strong claims that automakers often promote about their plug-in hybrid vehicles are clearly way off the truth,” stated a automotive expert. “Consumers are being duped into believing that by purchasing a PHEV, they are helping the planet and saving money. In reality, PHEVs are little better than regular petrol and diesel cars in terms of energy consumption, CO₂ production, and operating costs.”

Policy Discussion and Industry Pressure

Hybrid cars have recently been drawn back into political discussions as automakers have lobbied the European Union to relax CO₂ standards. A proposed ban on sales of new internal combustion vehicles in 2035 has faced intense pressure from the car sector and resistance from member states with significant car manufacturing.

Several high-level officials have proposed plug-in hybrids as a potential “compromise” solution to include in the legislation.

An external energy economics specialist, who was not involved with the study, described the report a “very useful contribution” after years in which segments of the automotive sector claimed there was too little information to properly evaluate real-world CO2 output.

“The results show, without question, that the difference between official and real-world PHEV fuel consumption and CO₂ emissions is significantly larger than for gasoline or diesel cars,” the expert stated. “All policy adjustments regarding PHEVs should be made with extreme caution and considering this evidence.”