Plug-in Hybrid electric Cars Pollute Nearly as Heavily as Gasoline Vehicles, Report Finds

Plug-in hybrid electric vehicles produce almost five times more planet-heating emissions than official figures show, as per a recent report.

Growing Discrepancy In Lab and Actual CO2 Output

Statistics shows that PHEVs emit just 19% lower CO₂ than conventional gas and diesel cars, based on research conducted by a non-profit organization. This contrasts significantly with laboratory estimates, which suggested a three-quarters reduction in emissions.

Analysts studied data from in-vehicle energy use monitors of eight hundred thousand cars registered in the EU from 2021 and 2023. The team discovered that actual CO₂ output from PHEVs in 2023 were 4.9 times higher than lab estimates, up from three and a half times in 2021.

“Real-world CO2 output are increasing, while official figures are decreasing,” said a senior analyst involved in the study. “That gap is widening and poses a significant problem. Consequently, PHEVs pollute nearly as heavily as petrol cars.”

Primary Factors Driving the Discrepancy

Researchers linked the majority of the gap to inflated estimates of the “utility factor” – the percentage of kilometers driven in electric mode relative to total distance. The team determined that just a quarter of driving was done in EV mode, whereas lab assumptions suggested 84%.

Even, when operating in EV mode, emission amounts were significantly higher than official projections. That happened because EV motors were not strong enough to function independently, leading to combustion motors using gasoline for almost a third of the travel covered in EV mode.

Regulatory and Financial Implications

According to estimates, the lowballing of PHEV CO2 output enabled four large carmaker companies to avoid more than €5bn in penalties from 2021 and 2023, by artificially easing adherence with European Union average fleet CO₂ targets.

Additionally, owners of PHEVs could pay about €500 extra per year in operating expenses than is assumed under lab conditions.

“The strong statements that manufacturers like to make about their PHEV vehicles are obviously way off the truth,” stated a automotive analyst. “Consumers are being misled into thinking that by buying a PHEV, they are benefiting the environment and cutting money. In reality, PHEVs are little improved than standard petrol and diesel cars in terms of energy consumption, CO₂ emissions, and running costs.”

Policy Debate and Automotive Pressure

Plug-in hybrid vehicles have recently been drawn back into policy debates as automakers have lobbied the European Union to relax CO₂ standards. A proposed ban on new internal combustion vehicles in 2035 has faced intense pressure from the car sector and opposition from EU countries with large automotive manufacturing.

Some high-level politicians have proposed PHEVs as a possible “compromise” solution to include in the regulation.

An independent energy policy expert, who was not involved with the research, called the report a “very useful contribution” after a long period in which segments of the automotive industry claimed there was too little data to accurately assess actual CO2 output.

“These findings show, beyond any doubt, that the difference in official and actual PHEV fuel consumption and CO₂ emissions is much, much greater than for gasoline or diesel cars,” they stated. “All regulatory adjustments regarding PHEVs should be implemented with utmost care and in the light of this data.”