Plug-in Hybrid electric Cars Emit Almost as Heavily as Gasoline Vehicles, Study Finds

Plug-in hybrid cars release nearly 5x more global warming emissions than official figures show, as per a recent analysis.

Growing Discrepancy In Lab and Actual CO2 Output

Data reveals that PHEVs release just one-fifth lower CO₂ than conventional gas and diesel cars, according to analysis conducted by a advocacy group. That contrasts sharply with lab tests, which assumed a 75% reduction in emissions.

Analysts studied data from onboard fuel consumption meters of eight hundred thousand vehicles registered in Europe between 2021 and 2023. The team discovered that actual CO₂ emissions from PHEVs in 2023 were nearly five times higher than official estimates, increased from 3.5 times in 2021.

“Real-world CO2 output are rising, while lab-reported emissions are falling,” said a lead analyst participating in the study. “This gap is widening and poses a significant issue. Consequently, PHEVs emit almost as heavily as gasoline vehicles.”

Key Factors Behind the Emissions Gap

Researchers linked the majority of the gap to overestimates of the “utility factor” – the percentage of kilometers travelled in electric mode compared to total mileage. They determined that just 27% of travel was completed in electric mode, while lab assumptions assumed 84%.

Additionally, when running in electric mode, emission levels were significantly higher than lab projections. That happened because electric motors were not strong enough to operate independently, leading to combustion motors burning fossil fuels for almost one-third of the travel completed in electric mode.

Regulatory and Financial Implications

According to calculations, the lowballing of PHEV emissions allowed several large carmaker groups to avoid over €5bn in penalties from 2021 and 2023, by artificially easing compliance with European Union fleet-average CO₂ standards.

Furthermore, owners of PHEVs would pay about €500 more annually in running costs than is estimated under lab conditions.

“The strong claims that automakers like to make about their plug-in hybrid cars are clearly far from the truth,” commented a automotive analyst. “Consumers are being duped into thinking that by buying a PHEV, they are benefiting the environment and saving money. Actually, PHEVs are little improved than standard gas and diesel cars in terms of energy consumption, CO₂ emissions, and running costs.”

Policy Discussion and Industry Lobbying

Hybrid cars have lately been drawn back into political debates as automakers have pressed the EU to relax CO₂ standards. A proposed prohibition on new internal combustion vehicles in 2035 has faced intense pressure from the car industry and resistance from EU countries with large car manufacturing.

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

One external energy policy specialist, who was not involved with the research, called the report a “very useful contribution” after a long period in which parts of the automotive industry argued there was too little information to properly assess actual emissions.

“The results demonstrate, beyond any doubt, that the gap between official and actual PHEV energy use and CO₂ emissions is much, much greater than for gasoline or diesel cars,” the expert said. “Any policy adjustments regarding PHEVs should be made with extreme caution and considering that data.”