🔗 Share this article

PHEVs emit nearly 5x more global warming pollution than official data show, according to a recent report.

Widening Discrepancy In Lab and Actual Emissions

Data shows that PHEVs emit just one-fifth lower CO₂ than conventional petrol and diesel vehicles, based on research conducted by a advocacy group. That differs significantly with lab tests, which suggested a three-quarters reduction in emissions.

Researchers studied data from in-vehicle fuel consumption monitors of eight hundred thousand vehicles registered in Europe between 2021 and 2023. The team found that actual CO₂ output from PHEVs in 2023 were 4.9 times higher than lab figures, increased from three and a half times in 2021.

“Actual CO2 output are rising, while lab-reported figures are decreasing,” said a lead analyst participating in the report. “That gap is widening and poses a significant problem. As a result, PHEVs pollute almost as much as petrol cars.”

Primary Reasons Behind the Emissions Gap

Analysts attributed the majority of the gap to overestimates of the “electric driving share” – the percentage of miles driven in electric mode compared to total mileage. They determined that just 27% of travel was completed in EV mode, whereas lab estimates assumed over four-fifths.

Additionally, when running in electric mode, emission levels were significantly higher than official projections. This happened because EV motors were insufficiently powerful sufficient to function independently, leading to combustion motors burning gasoline for nearly a third of the distance completed in EV mode.

Policy and Economic Consequences

Based on calculations, the lowballing of PHEV CO2 output enabled several large carmaker companies to escape over €5bn in fines from 2021 and 2023, by falsely simplifying adherence with EU average fleet CO₂ standards.

Furthermore, owners of PHEVs could pay about €500 more per year in operating expenses than is estimated under laboratory conditions.

“The bold claims that automakers often promote about their plug-in hybrid cars are obviously way off the truth,” stated a automotive expert. “Buyers are being duped into believing that by purchasing a PHEV, they are benefiting the environment and cutting costs. In reality, PHEVs are only slightly better than standard gas and diesel cars in terms of fuel consumption, CO₂ emissions, and running costs.”

Policy Debate and Industry Pressure

Plug-in hybrid vehicles have lately been brought back into political discussions as carmakers have lobbied the European Union to relax CO₂ standards. A proposed prohibition on new combustion engine cars in 2035 has faced heavy lobbying from the automotive sector and resistance from member states with large car industries.

Several senior officials have suggested PHEVs as a possible “flexibility” solution to introduce in the regulation.

An external energy economics specialist, who was not involved with the study, called the report a “highly valuable addition” after years in which parts of the automotive sector claimed there was insufficient data to properly assess actual emissions.

“The results show, without question, that the difference in lab and real-world PHEV fuel consumption and CO₂ emissions is much, much larger than for petrol or diesel cars,” the expert stated. “All regulatory changes regarding PHEVs should be implemented with utmost caution and considering that data.”