🔗 Share this article

Plug-in hybrid cars produce almost five times greater planet-heating emissions than official figures show, as per a recent analysis.

Widening Discrepancy Between Official and Actual Emissions

Data reveals that PHEVs release just 19% lower CO₂ than traditional gas and diesel vehicles, based on analysis conducted by a non-profit organization. That contrasts significantly with lab estimates, which suggested a 75% decrease in pollution.

Analysts studied data from onboard energy use meters of eight hundred thousand vehicles registered in Europe from 2021 and 2023. The team discovered that actual CO₂ emissions from PHEVs in 2023 were nearly five times greater than lab figures, increased from three and a half times in 2021.

“Real-world emissions are rising, while lab-reported emissions are falling,” stated a senior analyst involved in the report. “This gap is growing and poses a serious problem. As a result, PHEVs emit almost as much as gasoline vehicles.”

Primary Reasons Behind the Discrepancy

Researchers linked most of the gap to overestimates of the “electric driving share” – the percentage of kilometers travelled in battery power relative to overall mileage. The team found that only 27% of driving was completed in EV mode, whereas official estimates suggested 84%.

Even, when running in EV mode, pollution levels were well above official estimates. That happened because electric motors were insufficiently powerful enough to operate independently, resulting to combustion motors burning gasoline for almost one-third of the distance covered in EV mode.

Policy and Economic Implications

According to estimates, the lowballing of PHEV CO2 output allowed four large automaker companies to escape more than €5bn in penalties from 2021 and 2023, by artificially easing adherence with European Union average fleet CO₂ targets.

Additionally, drivers of PHEVs could pay about €500 more annually in running costs than would be estimated under laboratory conditions.

“The bold claims that automakers often promote about their plug-in hybrid vehicles are obviously way off the truth,” commented a transport expert. “Buyers are being duped into thinking that by buying a PHEV, they are benefiting the planet and cutting money. Actually, PHEVs are little better than standard gas and diesel vehicles in terms of energy consumption, CO₂ emissions, and running expenses.”

Policy Debate and Automotive Pressure

Hybrid cars have recently been brought again into political debates as automakers have lobbied the EU to relax CO₂ standards. A planned ban on new combustion engine vehicles in 2035 has faced heavy pressure from the car sector and opposition from member states with significant automotive industries.

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

An external energy policy expert, who was unaffiliated with the research, called the report a “very useful contribution” after years in which segments of the automotive industry claimed there was too little information to accurately evaluate real-world CO2 output.

“The results show, without question, that the gap in lab and real-world PHEV energy use and CO₂ output is much, much larger than for petrol or diesel cars,” they stated. “Any policy adjustments concerning PHEVs should be implemented with utmost care and considering this data.”