🔗 Share this article

Plug-in hybrid electric vehicles emit almost 5x greater global warming emissions than official figures show, as per a new report.

Widening Gap Between Official and Actual CO2 Output

Statistics reveals that PHEVs emit only 19% lower CO₂ than conventional petrol and diesel vehicles, based on analysis conducted by a non-profit organization. This contrasts significantly with lab tests, which assumed a three-quarters reduction in pollution.

Analysts examined information from onboard fuel consumption meters of 800,000 cars sold in the EU from 2021 and 2023. The team discovered that actual CO₂ emissions from PHEVs in 2023 were 4.9 times higher than official figures, increased from three and a half times in 2021.

“Real-world CO2 output are increasing, while lab-reported emissions are decreasing,” said a senior researcher participating in the report. “That gap is growing and poses a significant problem. Consequently, PHEVs emit almost as much as petrol cars.”

Key Factors Behind the Emissions Gap

Analysts attributed the majority of the gap to inflated estimates of the “utility factor” – the ratio of miles driven in battery mode relative to overall mileage. They found that only a quarter of driving was done in electric mode, while official assumptions assumed over four-fifths.

Additionally, when running in electric mode, pollution levels were well above official estimates. That happened because electric motors were not strong enough to operate independently, leading to combustion motors burning fossil fuels for nearly one-third of the distance covered in electric mode.

Policy and Economic Consequences

Based on estimates, the lowballing of PHEV CO2 output allowed four large carmaker companies 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 more annually in operating expenses than would be estimated under laboratory tests.

“The strong claims that manufacturers like to make about their plug-in hybrid vehicles are clearly way off the mark,” commented a transport expert. “Buyers are being misled into thinking that by buying a PHEV, they are benefiting the environment and saving costs. Actually, PHEVs are little improved than standard gas and diesel cars in terms of energy consumption, CO₂ emissions, and running costs.”

Political Discussion and Industry Lobbying

Hybrid cars have lately been drawn back into policy discussions as automakers have lobbied the EU to weaken CO₂ targets. A planned prohibition on sales of new combustion engine vehicles in 2035 has faced heavy pressure from the car industry and opposition from member states with significant automotive industries.

Several high-level politicians have proposed PHEVs as a possible “flexibility” solution to introduce in the regulation.

An independent energy policy specialist, who was unaffiliated with the study, described the report a “highly valuable contribution” after years in which segments of the car sector argued there was too little data to accurately assess actual CO2 output.

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