Plug-in Hybrid electric Cars Emit Nearly as Much as Petrol Cars, Report Finds

Plug-in hybrid electric vehicles emit nearly 5x more global warming emissions than official figures indicate, according to a new report.

Widening Discrepancy In Lab and Real-World Emissions

Data shows that PHEVs release just one-fifth less CO₂ than conventional gas and diesel vehicles, based on research carried out by a non-profit organization. This differs sharply with lab tests, which suggested a three-quarters reduction in emissions.

Researchers studied data from onboard energy use meters of eight hundred thousand vehicles registered in Europe between 2021 and 2023. The team found that actual CO₂ emissions from PHEVs in 2023 were nearly five times greater than lab estimates, up from 3.5 times in 2021.

“Real-world emissions are increasing, while official figures are falling,” stated a senior analyst participating in the study. “This gap is widening and creates a significant problem. Consequently, PHEVs pollute nearly as heavily as gasoline vehicles.”

Primary Factors Behind the Discrepancy

Researchers linked most of the gap to overestimates of the “electric driving share” – the percentage of miles driven in battery power compared to total distance. The team found that only a quarter of driving was done in electric mode, while official assumptions suggested 84%.

Additionally, when operating in EV mode, pollution levels were well above lab estimates. This happened because electric motors were insufficiently powerful sufficient to function independently, leading to combustion motors using fossil fuels for almost one-third of the distance covered in EV mode.

Policy and Financial Consequences

According to estimates, the underestimation of PHEV emissions allowed four large automaker groups to avoid over €5bn in penalties from 2021 and 2023, by falsely easing adherence with EU average fleet CO₂ standards.

Furthermore, drivers of PHEVs would pay about €500 more per year in running expenses than would be estimated under lab conditions.

“The strong claims that manufacturers like to make about their PHEV vehicles are obviously far from the truth,” stated a automotive analyst. “Consumers are being duped into believing that by buying a PHEV, they are benefiting the planet and cutting costs. Actually, PHEVs are only slightly better than regular gas and diesel vehicles in terms of fuel use, CO₂ production, and operating costs.”

Political Debate and Automotive Lobbying

Hybrid vehicles have lately been drawn again into political debates as automakers have pressed the EU to relax CO₂ targets. A proposed ban on new combustion engine vehicles in 2035 has faced intense lobbying from the car industry and resistance from member states with significant automotive manufacturing.

Several senior officials have proposed PHEVs as a potential “flexibility” solution to include in the legislation.

An independent energy economics expert, who was not involved with the research, described the analysis a “highly valuable contribution” after years in which parts of the automotive industry argued there was insufficient information to properly evaluate real-world CO2 output.

“The results demonstrate, beyond any doubt, that the gap in official and actual PHEV energy use and CO₂ output is significantly larger than for petrol or conventional cars,” they said. “Any regulatory adjustments concerning PHEVs should be made with extreme caution and in the light of that data.”