Plug in Hybrid Vehicles Pollute Almost as Heavily as Petrol Vehicles, Study Reveals

Plug-in hybrid electric vehicles produce nearly 5x greater global warming emissions than lab-reported figures indicate, as per a recent report.

Widening Discrepancy Between Lab and Actual Emissions

Data shows that PHEVs emit only 19% less CO₂ than traditional gas and diesel cars, based on analysis carried out by a non-profit organization. That differs significantly with laboratory estimates, which suggested a 75% decrease in pollution.

Analysts examined information from in-vehicle fuel consumption monitors of 800,000 cars sold in Europe from 2021 and 2023. They discovered that real-world CO₂ output from PHEVs in 2023 were nearly five times higher than lab figures, up from 3.5 times in 2021.

“Actual emissions are increasing, while lab-reported figures are decreasing,” stated a senior researcher participating in the study. “This discrepancy is widening and creates a significant problem. Consequently, PHEVs pollute nearly as heavily as gasoline vehicles.”

Primary Factors Behind the Discrepancy

Analysts linked most of the gap to overestimates of the “utility factor” – the percentage of kilometers travelled in electric mode compared to total mileage. They found that only a quarter of travel was done in electric mode, while lab estimates assumed 84%.

Additionally, when operating in electric mode, emission amounts were well above official projections. This occurred because electric motors were not strong enough to operate independently, leading to engines using gasoline for almost a third of the distance completed in EV mode.

Policy and Economic Implications

According to estimates, the lowballing of PHEV emissions enabled several large automaker groups to escape over €5bn in fines from 2021 and 2023, by falsely simplifying adherence with European Union average fleet CO₂ targets.

Additionally, owners of PHEVs would pay approximately €500 extra annually in running expenses than is estimated under laboratory tests.

“The strong statements that automakers like to make about their plug-in hybrid vehicles are obviously far from the mark,” commented a automotive analyst. “Buyers are being misled into thinking that by purchasing a PHEV, they are helping the planet and saving money. In reality, PHEVs are only slightly improved than standard gas and diesel cars in terms of fuel consumption, CO₂ production, and running costs.”

Political Debate and Automotive Lobbying

Hybrid vehicles have lately been drawn back into policy discussions as carmakers have lobbied the EU to relax CO₂ standards. A planned prohibition on sales of new internal combustion vehicles in 2035 has faced heavy lobbying from the car sector and resistance from member states with large car manufacturing.

Some high-level politicians have suggested plug-in hybrids as a potential “compromise” solution to include in the legislation.

An independent energy economics specialist, who was not involved with the study, described the analysis a “very useful contribution” after years in which segments of the car sector claimed there was insufficient information to accurately assess actual emissions.

“These findings show, without question, that the gap in lab and real-world PHEV fuel consumption and CO₂ output is much, much greater than for gasoline or diesel cars,” they said. “All policy adjustments regarding PHEVs should be made with extreme care and considering that evidence.”