🔗 Share this article

Plug-in hybrid electric vehicles emit nearly 5x greater planet-heating emissions than lab-reported data indicate, as per a new analysis.

Widening Discrepancy In Official and Real-World Emissions

Statistics reveals that PHEVs release only one-fifth lower CO₂ than traditional gas and diesel vehicles, based on research carried out by a advocacy organization. This contrasts sharply with lab estimates, which suggested a 75% reduction in emissions.

Researchers examined data from in-vehicle fuel consumption monitors of eight hundred thousand vehicles registered in Europe between 2021 and 2023. They discovered that real-world CO₂ emissions from PHEVs in 2023 were 4.9 times higher than official estimates, increased from three and a half times in 2021.

“Real-world CO2 output are rising, while lab-reported emissions are decreasing,” said a senior analyst involved in the report. “This gap is widening and creates a serious problem. Consequently, PHEVs emit nearly as heavily as gasoline cars.”

Key Factors Behind the Discrepancy

Analysts linked most of the difference to overestimates of the “utility factor” – the ratio of miles travelled in electric mode compared to overall mileage. The team determined that only a quarter of travel was done in electric mode, whereas lab estimates suggested over four-fifths.

Additionally, when running in electric mode, emission levels were significantly higher than official estimates. This happened because electric motors were not strong sufficient to operate alone, leading to combustion motors burning fossil fuels for nearly one-third of the travel completed in electric mode.

Policy and Financial Consequences

According to estimates, the lowballing of PHEV emissions enabled four large carmaker groups to avoid more than €5bn in penalties from 2021 and 2023, by falsely simplifying compliance with European Union average fleet CO₂ targets.

Furthermore, drivers of PHEVs would spend about €500 more annually in running costs than is estimated under laboratory tests.

“The strong claims that manufacturers like to make about their PHEV vehicles are clearly far from the mark,” commented a automotive analyst. “Consumers are being duped into thinking that by purchasing a PHEV, they are helping the planet and cutting money. In reality, PHEVs are little better than regular petrol and diesel cars in terms of energy consumption, CO₂ emissions, and operating expenses.”

Political Discussion and Automotive Lobbying

Hybrid vehicles have lately been drawn back into policy discussions as carmakers have pressed the EU to weaken CO₂ targets. A proposed ban on sales of new combustion engine vehicles in 2035 has faced heavy pressure from the automotive sector and opposition from member states with significant car manufacturing.

Some senior politicians have suggested PHEVs as a possible “compromise” option to introduce in the legislation.

An external energy policy specialist, who was unaffiliated with the research, described the report a “highly valuable addition” after years in which segments of the automotive sector argued there was insufficient information to accurately assess actual CO2 output.

“These findings demonstrate, without question, that the gap between lab and real-world PHEV energy use and CO₂ output is much, much greater than for gasoline or diesel vehicles,” the expert said. “All regulatory adjustments regarding PHEVs should be implemented with extreme care and in the light of this evidence.”