🔗 Share this article

Plug-in hybrid cars release almost 5x more planet-heating pollution than lab-reported figures show, as per a new analysis.

Widening Discrepancy In Lab and Actual Emissions

Data reveals that PHEVs emit only one-fifth lower CO₂ than conventional petrol and diesel cars, based on research carried out by a advocacy organization. This contrasts significantly with lab estimates, which assumed a 75% decrease in emissions.

Analysts studied information from in-vehicle fuel consumption meters of eight hundred thousand vehicles sold in the EU between 2021 and 2023. They discovered that real-world CO₂ emissions from PHEVs in 2023 were 4.9 times greater than official figures, up from 3.5 times in 2021.

“Real-world emissions are rising, while official emissions are falling,” stated a lead researcher involved in the report. “This gap is widening and poses a significant issue. As a result, PHEVs emit nearly as much as gasoline vehicles.”

Primary Factors Behind the Emissions Gap

Analysts attributed most of the difference to overestimates of the “electric driving share” – the percentage of kilometers driven in battery mode relative to total mileage. The team determined that just 27% of driving was done in EV mode, whereas lab assumptions suggested over four-fifths.

Even, when running in EV mode, emission amounts were well above lab projections. That happened because EV motors were insufficiently powerful enough to function independently, leading to engines burning gasoline for almost a third of the distance completed in EV mode.

Regulatory and Financial Consequences

According to estimates, the underestimation of PHEV emissions enabled several large carmaker groups to escape more than €5bn in penalties from 2021 and 2023, by artificially simplifying compliance with European Union fleet-average CO₂ standards.

Additionally, drivers of PHEVs could spend approximately €500 extra per year in running expenses than would be assumed under laboratory conditions.

“The strong claims that automakers like to make about their plug-in hybrid vehicles are clearly far from the mark,” stated a transport analyst. “Consumers are being duped into thinking that by buying a PHEV, they are benefiting the environment and cutting costs. Actually, PHEVs are only slightly better than regular gas and diesel vehicles in terms of energy use, CO₂ production, and operating costs.”

Political Debate and Industry Lobbying

Hybrid cars have lately been brought again into policy debates as automakers have pressed the EU to weaken CO₂ standards. A proposed ban on new combustion engine vehicles in 2035 has faced heavy pressure from the car industry and resistance from EU countries with large automotive industries.

Some senior officials have suggested PHEVs as a possible “flexibility” option to include in the legislation.

One external energy economics specialist, who was not involved with the research, called the report a “highly valuable addition” after years in which parts of the automotive sector claimed there was insufficient data to accurately evaluate real-world emissions.

“These findings demonstrate, beyond any doubt, that the gap in official and real-world PHEV fuel consumption and CO₂ emissions is significantly greater than for gasoline or conventional vehicles,” the expert said. “All policy changes regarding PHEVs should be implemented with utmost caution and in the light of this data.”