Plug-in Hybrid Cars Pollute Almost as Heavily as Petrol Vehicles, Report Reveals

Plug-in hybrid cars produce nearly five times more planet-heating pollution than lab-reported figures show, as per a new report.

Widening Discrepancy In Official and Actual Emissions

Data reveals that PHEVs emit only one-fifth less CO₂ than traditional petrol and diesel vehicles, based on research carried out by a non-profit organization. This differs significantly with laboratory estimates, which suggested a 75% decrease in emissions.

Researchers studied information from onboard energy use monitors of 800,000 cars sold in the EU from 2021 and 2023. They discovered that actual CO₂ emissions from PHEVs in 2023 were 4.9 times greater than official figures, up from three and a half times in 2021.

“Real-world emissions are rising, while lab-reported figures are falling,” stated a senior analyst involved in the study. “That discrepancy is widening and poses a serious issue. As a result, PHEVs pollute almost as much as petrol vehicles.”

Key Factors Behind the Discrepancy

Analysts linked most of the gap to overestimates of the “electric driving share” – the ratio of kilometers travelled in battery mode relative to overall distance. They determined that just a quarter of travel was done in EV mode, whereas lab estimates assumed over four-fifths.

Additionally, when operating in EV mode, emission amounts were well above lab projections. This happened because electric motors were not strong enough to operate alone, resulting to combustion motors burning fossil fuels for almost a third of the distance covered in EV mode.

Regulatory and Economic Consequences

Based on calculations, the lowballing of PHEV emissions enabled four major automaker companies to avoid over €5bn in penalties from 2021 and 2023, by falsely simplifying compliance with EU average fleet CO₂ standards.

Additionally, drivers of PHEVs could pay approximately €500 extra per year in running expenses than would be assumed under lab conditions.

“The strong claims that manufacturers like to make about their plug-in hybrid vehicles are obviously far from the truth,” commented a automotive expert. “Consumers are being duped into thinking that by purchasing a PHEV, they are helping the environment and saving money. Actually, PHEVs are little improved than standard petrol and diesel cars in terms of energy consumption, CO₂ production, and operating costs.”

Political Debate and Automotive Lobbying

Plug-in hybrid vehicles have lately been brought again into policy discussions as automakers have pressed the EU to relax CO₂ targets. A planned prohibition on new combustion engine cars in 2035 has faced heavy lobbying from the car sector and resistance from EU countries with large car industries.

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

An independent energy economics specialist, who was not involved with the research, called the report a “very useful contribution” after years in which parts of the automotive sector argued there was too little information to properly assess real-world CO2 output.

“The results show, without question, that the gap in official and real-world PHEV fuel consumption and CO₂ output is significantly greater than for petrol or conventional vehicles,” they said. “Any policy changes concerning PHEVs should be implemented with extreme caution and in the light of this data.”