🔗 Share this article

PHEVs release almost five times greater planet-heating emissions than lab-reported data show, according to a recent analysis.

Widening Discrepancy In Official and Real-World CO2 Output

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

Analysts examined information from onboard fuel consumption monitors of 800,000 vehicles registered in Europe from 2021 and 2023. The team found that actual CO₂ output from PHEVs in 2023 were nearly five times higher than lab figures, increased from three and a half times in 2021.

“Real-world emissions are increasing, while official emissions are falling,” stated a lead analyst involved in the report. “That discrepancy is widening and poses a serious problem. Consequently, PHEVs emit nearly as heavily as petrol cars.”

Key Factors Driving the Discrepancy

Researchers linked the majority of the difference to overestimates of the “utility factor” – the percentage of kilometers travelled in battery power relative to total mileage. They found that just a quarter of travel was completed in EV mode, while official assumptions assumed over four-fifths.

Additionally, when running in EV mode, emission amounts were significantly higher than lab estimates. This occurred because EV motors were insufficiently powerful sufficient to function alone, resulting to combustion motors burning gasoline for almost one-third of the distance completed in electric mode.

Policy and Economic Implications

According to estimates, the underestimation of PHEV emissions enabled several major automaker companies to escape more than €5bn in penalties between 2021 and 2023, by artificially easing compliance with European Union average fleet CO₂ standards.

Additionally, owners of PHEVs could pay about €500 extra annually in running expenses than is estimated under laboratory tests.

“The bold claims that automakers like to make about their PHEV vehicles are obviously way off the truth,” commented a automotive expert. “Buyers are being misled into thinking that by purchasing a PHEV, they are helping the planet and saving money. Actually, PHEVs are only slightly improved than regular gas and diesel vehicles in terms of energy use, CO₂ production, and running costs.”

Political Discussion and Industry Lobbying

Plug-in hybrid cars have recently been brought again into policy debates as automakers have pressed the EU to relax CO₂ targets. A proposed prohibition on sales of new combustion engine vehicles in 2035 has faced heavy lobbying from the car sector and resistance from EU countries with significant automotive industries.

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

An independent energy policy specialist, who was unaffiliated with the study, described the analysis a “very useful contribution” after years in which segments of the car sector argued there was too little data to properly assess real-world CO2 output.

“The results show, without question, that the gap in official and actual PHEV energy use and CO₂ output is significantly greater than for petrol or diesel vehicles,” the expert stated. “All regulatory changes concerning PHEVs should be implemented with utmost caution and considering that evidence.”