🔗 Share this article

Plug-in hybrid cars produce almost 5x greater planet-heating emissions than lab-reported data indicate, as per a recent analysis.

Widening Gap Between Official and Real-World Emissions

Statistics reveals that PHEVs emit only one-fifth less CO₂ than conventional gas and diesel vehicles, according to analysis conducted by a non-profit organization. This contrasts significantly with laboratory estimates, which suggested a three-quarters reduction in pollution.

Researchers examined information from onboard fuel consumption meters of eight hundred thousand vehicles registered in Europe between 2021 and 2023. The team discovered that real-world CO₂ output from PHEVs in 2023 were 4.9 times greater than lab estimates, increased from three and a half times in 2021.

“Real-world emissions are rising, while lab-reported emissions are falling,” said a senior analyst involved in the report. “This gap is growing and creates a serious problem. As a result, PHEVs pollute almost as much as gasoline vehicles.”

Primary Reasons Behind the Discrepancy

Analysts attributed the majority of the difference to inflated estimates of the “electric driving share” – the percentage of kilometers travelled in battery power relative to overall mileage. The team determined that just a quarter of travel was done in EV mode, while lab estimates suggested over four-fifths.

Additionally, when operating in electric mode, emission amounts were well above lab estimates. This occurred because EV motors were insufficiently powerful sufficient to operate independently, leading to engines burning fossil fuels for nearly a third of the distance completed in electric mode.

Policy and Economic Implications

Based on calculations, the underestimation of PHEV emissions enabled several large automaker groups to escape over €5bn in penalties between 2021 and 2023, by falsely easing adherence with EU fleet-average CO₂ targets.

Additionally, owners of PHEVs would spend approximately €500 extra annually in running costs than would be estimated under lab tests.

“The bold statements that manufacturers like to make about their PHEV vehicles are obviously way off the mark,” commented a automotive analyst. “Consumers are being duped into believing that by purchasing a PHEV, they are helping the environment and cutting money. In reality, PHEVs are only slightly better than regular gas and diesel cars in terms of fuel consumption, CO₂ production, and operating costs.”

Policy Debate and Automotive Pressure

Plug-in hybrid vehicles have lately been brought again into policy debates as carmakers have pressed the EU to relax CO₂ standards. A planned ban on new internal combustion cars in 2035 has faced heavy pressure from the automotive sector and opposition from member states with large car manufacturing.

Some senior officials have proposed PHEVs as a potential “flexibility” option to include in the regulation.

An independent energy economics specialist, who was unaffiliated with the study, described the report a “very useful contribution” after years in which segments of the automotive sector argued there was too little information to accurately evaluate real-world CO2 output.

“The results demonstrate, without question, that the gap in official and actual PHEV fuel consumption and CO₂ emissions is much, much larger than for gasoline or diesel cars,” they stated. “Any policy changes regarding PHEVs should be implemented with extreme caution and considering that data.”