🔗 Share this article

Plug-in hybrid electric vehicles produce almost five times greater global warming emissions than lab-reported data show, as per a recent report.

Growing Gap In Official and Real-World CO2 Output

Data shows that PHEVs emit only one-fifth less CO₂ than traditional gas and diesel vehicles, according to research carried out by a non-profit group. This differs sharply with lab tests, which assumed a 75% decrease in pollution.

Researchers examined information from onboard energy use monitors of 800,000 vehicles sold in the EU between 2021 and 2023. The team found that actual CO₂ emissions from PHEVs in 2023 were nearly five times greater than official estimates, increased from 3.5 times in 2021.

“Real-world CO2 output are increasing, while official figures are decreasing,” said a lead analyst participating in the report. “This discrepancy is widening and poses a significant issue. As a result, PHEVs pollute nearly as heavily as petrol vehicles.”

Key Factors Behind the Emissions Gap

Researchers attributed most of the gap to inflated estimates of the “utility factor” – the ratio of miles travelled in electric power relative to total distance. They determined that just a quarter of driving was completed in electric mode, whereas lab estimates suggested 84%.

Even, when running in electric mode, emission levels were significantly higher than official estimates. This occurred because EV motors were not strong enough to operate independently, leading to combustion motors burning fossil fuels for almost a third of the distance covered in EV mode.

Regulatory and Financial Consequences

According to estimates, the underestimation of PHEV CO2 output enabled four major automaker companies to escape over €5bn in fines from 2021 and 2023, by falsely simplifying adherence with European Union average fleet CO₂ standards.

Furthermore, owners of PHEVs could pay approximately €500 extra annually in running expenses than is estimated under lab conditions.

“The bold claims that manufacturers like to make about their PHEV vehicles are clearly far from the truth,” stated a transport expert. “Consumers are being duped into thinking that by purchasing a PHEV, they are benefiting the environment and saving costs. In reality, PHEVs are only slightly improved than regular petrol and diesel vehicles in terms of energy use, CO₂ emissions, and operating expenses.”

Policy Discussion and Automotive Pressure

Hybrid vehicles have lately been drawn back into policy debates as automakers have pressed the European Union to weaken CO₂ targets. A proposed prohibition on new internal combustion vehicles in 2035 has faced heavy lobbying from the automotive sector and resistance from member states with significant automotive manufacturing.

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

An external energy economics expert, who was unaffiliated with the study, described the report a “very useful addition” after a long period in which parts of the automotive industry argued there was insufficient information to properly assess real-world emissions.

“The results show, beyond any doubt, that the gap between lab and actual PHEV fuel consumption and CO₂ emissions is significantly greater than for petrol or diesel vehicles,” the expert stated. “All policy changes regarding PHEVs should be made with extreme caution and considering this data.”