🔗 Share this article

Plug-in hybrid cars emit almost 5x greater planet-heating emissions than lab-reported figures show, as per a new analysis.

Growing Gap In Lab and Actual CO2 Output

Data reveals that PHEVs release just one-fifth lower CO₂ than traditional gas and diesel cars, according to research carried out by a advocacy organization. This differs sharply with laboratory estimates, which assumed a three-quarters decrease in emissions.

Researchers examined data from in-vehicle fuel consumption meters of eight hundred thousand cars sold in the EU from 2021 and 2023. The team found that real-world CO₂ emissions from PHEVs in 2023 were nearly five times greater than lab estimates, increased from 3.5 times in 2021.

“Real-world emissions are rising, while official figures are falling,” said a lead analyst involved in the report. “This discrepancy is growing and poses a serious problem. As a result, PHEVs pollute nearly as heavily as gasoline vehicles.”

Key Reasons Driving the Discrepancy

Researchers attributed the majority of the difference to inflated estimates of the “utility factor” – the ratio of miles driven in battery mode compared to overall mileage. They found that just a quarter of driving was completed in EV mode, while official estimates assumed 84%.

Additionally, when running in electric mode, pollution levels were well above lab projections. That happened because electric motors were insufficiently powerful sufficient to operate independently, leading to engines burning fossil fuels for almost a third of the travel completed in electric mode.

Regulatory and Financial Consequences

Based on estimates, the underestimation of PHEV emissions enabled several large carmaker companies to avoid over €5bn in fines from 2021 and 2023, by falsely simplifying compliance with European Union average fleet CO₂ standards.

Additionally, owners of PHEVs would pay approximately €500 extra per year in running costs than is assumed under lab conditions.

“The bold claims that manufacturers often promote about their plug-in hybrid cars are obviously way off the truth,” stated a automotive expert. “Consumers are being duped into thinking that by purchasing a PHEV, they are benefiting the planet and saving money. In reality, PHEVs are little better than standard gas and diesel vehicles in terms of fuel consumption, CO₂ production, and operating costs.”

Policy Debate and Industry Lobbying

Hybrid vehicles have lately been drawn back into policy debates as carmakers have pressed the European Union to weaken CO₂ targets. A proposed ban on new internal combustion vehicles in 2035 has faced intense lobbying from the car industry and opposition from member states with significant automotive industries.

Several high-level officials have proposed PHEVs as a potential “compromise” option to introduce in the regulation.

One independent energy policy specialist, who was unaffiliated with the study, called the report a “highly valuable contribution” after a long period in which segments of the automotive industry argued there was too little data to accurately assess actual emissions.

“These findings show, without question, that the gap between lab and actual PHEV fuel consumption and CO₂ output is much, much larger than for gasoline or conventional vehicles,” they said. “Any policy adjustments regarding PHEVs should be implemented with extreme caution and considering this data.”