🔗 Share this article

Plug-in hybrid electric vehicles emit nearly five times greater global warming pollution than lab-reported figures show, as per a recent analysis.

Growing Gap Between Lab and Real-World CO2 Output

Statistics reveals that PHEVs release just one-fifth less CO₂ than conventional gas and diesel vehicles, based on analysis carried out by a advocacy group. This contrasts significantly with laboratory tests, which suggested a three-quarters reduction in emissions.

Analysts studied information from onboard fuel consumption monitors of 800,000 vehicles registered in Europe from 2021 and 2023. They found that actual CO₂ emissions from PHEVs in 2023 were nearly five times greater than official figures, increased from 3.5 times in 2021.

“Actual CO2 output are rising, while official emissions are falling,” stated a senior analyst participating in the report. “That gap is growing and poses a serious problem. Consequently, PHEVs pollute nearly as heavily as petrol cars.”

Key Factors Driving the Discrepancy

Analysts attributed most of the gap to overestimates of the “utility factor” – the percentage of kilometers travelled in battery power compared to total distance. They determined that just 27% of travel was completed in EV mode, while lab assumptions assumed over four-fifths.

Additionally, when running in electric mode, pollution amounts were significantly higher than lab projections. That occurred because electric motors were not strong sufficient to function independently, leading to engines using fossil fuels for nearly a third of the distance completed in electric mode.

Regulatory and Financial Implications

Based on estimates, the lowballing of PHEV CO2 output allowed four major automaker companies to avoid over €5bn in fines between 2021 and 2023, by falsely easing adherence with European Union average fleet CO₂ standards.

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

“The strong statements that automakers like to make about their PHEV vehicles are obviously far from the truth,” commented a transport expert. “Buyers are being misled into believing that by buying a PHEV, they are benefiting the planet and saving costs. In reality, PHEVs are little better than standard gas and diesel vehicles in terms of energy use, CO₂ emissions, and running expenses.”

Policy Discussion and Automotive Pressure

Plug-in hybrid vehicles have lately been drawn again into policy debates as carmakers have lobbied the EU to weaken CO₂ standards. A proposed prohibition on new combustion engine cars in 2035 has faced intense lobbying from the automotive industry and resistance from EU countries with large car manufacturing.

Several high-level politicians have suggested plug-in hybrids as a potential “compromise” option to introduce in the regulation.

One external energy economics specialist, who was unaffiliated with the research, described the analysis a “very useful addition” after years in which parts of the car sector argued there was too little data to properly evaluate actual emissions.

“These findings demonstrate, without question, that the gap in lab and real-world PHEV fuel consumption and CO₂ emissions is much, much larger than for gasoline or diesel vehicles,” they said. “All regulatory adjustments concerning PHEVs should be implemented with utmost caution and considering that data.”