Plug-in Hybrid electric Vehicles Pollute Almost as Much as Petrol Vehicles, Report Finds

PHEVs produce almost five times greater planet-heating emissions than lab-reported figures indicate, as per a new report.

Widening Gap Between Lab and Actual CO2 Output

Statistics shows that PHEVs release just 19% less CO₂ than traditional petrol and diesel cars, based on analysis conducted by a advocacy organization. This contrasts significantly with laboratory estimates, which assumed a three-quarters reduction in pollution.

Analysts examined data from onboard energy use monitors of 800,000 cars registered in the EU from 2021 and 2023. The team discovered that actual CO₂ emissions from PHEVs in 2023 were 4.9 times higher than lab figures, increased from three and a half times in 2021.

“Actual emissions are rising, while official figures are decreasing,” said a lead analyst participating in the report. “That gap is widening and poses a significant issue. As a result, PHEVs pollute almost as heavily as gasoline cars.”

Primary Reasons Driving the Discrepancy

Analysts attributed most of the gap to overestimates of the “electric driving share” – the ratio of miles travelled in battery mode compared to total distance. The team found that only a quarter of driving was done in electric mode, while lab assumptions assumed 84%.

Additionally, when running in electric mode, pollution levels were significantly higher than lab projections. This happened because EV 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.

Policy and Financial Implications

Based on calculations, the lowballing of PHEV CO2 output allowed four major carmaker companies to escape more than €5bn in penalties between 2021 and 2023, by falsely easing compliance with European Union average fleet CO₂ standards.

Furthermore, drivers of PHEVs would pay about €500 extra annually in operating expenses than would be assumed under lab tests.

“The bold statements that manufacturers often promote about their plug-in hybrid vehicles are obviously way off the mark,” commented a transport expert. “Buyers are being duped into thinking that by buying a PHEV, they are helping the planet and cutting costs. Actually, PHEVs are little improved than regular gas and diesel cars in terms of fuel consumption, CO₂ production, and running costs.”

Political Discussion and Industry Pressure

Hybrid vehicles have lately been drawn again into policy discussions as automakers have pressed the EU to weaken CO₂ targets. A proposed ban 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 industries.

Some senior politicians have suggested plug-in hybrids as a possible “compromise” option to introduce in the legislation.

One independent energy economics expert, who was not involved with the study, called the analysis a “very useful contribution” after years in which segments of the car sector argued there was insufficient data to accurately assess actual CO2 output.

“These findings demonstrate, without question, that the difference between official and actual PHEV fuel consumption and CO₂ emissions is much, much greater than for petrol or conventional vehicles,” they said. “All regulatory changes regarding PHEVs should be made with extreme caution and in the light of that evidence.”