Plug-in Hybrid electric Vehicles Pollute Almost as Much as Gasoline Cars, Study Finds

Plug-in hybrid electric vehicles produce almost five times greater global warming emissions than lab-reported data show, as per a new report.

Widening Gap In Lab and Actual CO2 Output

Statistics shows that PHEVs release just one-fifth lower CO₂ than conventional petrol and diesel cars, according to analysis carried out by a advocacy organization. This contrasts significantly with lab estimates, which suggested a three-quarters reduction in pollution.

Analysts studied data from onboard energy use monitors of 800,000 cars registered in the EU between 2021 and 2023. They discovered that actual CO₂ output from PHEVs in 2023 were 4.9 times greater than official estimates, increased from 3.5 times in 2021.

“Actual CO2 output are rising, while lab-reported emissions are falling,” said a senior researcher involved in the study. “That gap is growing and poses a significant issue. As a result, PHEVs pollute almost as much as gasoline cars.”

Primary Reasons Behind the Discrepancy

Analysts attributed the majority of the difference to overestimates of the “electric driving share” – the ratio of miles travelled in electric mode compared to total distance. The team determined that just a quarter of driving was done in EV mode, whereas lab estimates assumed over four-fifths.

Even, when operating in EV mode, pollution levels were well above lab projections. That happened because electric motors were insufficiently powerful enough to operate alone, resulting to combustion motors burning gasoline for nearly one-third of the distance completed in EV mode.

Regulatory and Financial Implications

According to calculations, the lowballing of PHEV CO2 output allowed several major carmaker groups to avoid more than €5bn in penalties from 2021 and 2023, by artificially easing compliance with European Union average fleet CO₂ standards.

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

“The bold claims that manufacturers like to make about their plug-in hybrid vehicles are clearly far from the truth,” stated a automotive expert. “Consumers are being misled into believing that by purchasing a PHEV, they are helping the planet and saving costs. In reality, PHEVs are only slightly better than regular gas and diesel cars in terms of fuel use, CO₂ production, and running costs.”

Political Debate and Industry Lobbying

Hybrid vehicles have lately been brought back into political debates as carmakers have lobbied the European Union to relax CO₂ standards. A proposed prohibition on new combustion engine vehicles in 2035 has faced heavy lobbying from the automotive industry and resistance from member states with large car manufacturing.

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

One independent energy economics specialist, who was unaffiliated with the study, described the report a “highly valuable contribution” after a long period in which parts of the car industry argued there was too little information to properly assess real-world CO2 output.

“The results show, without question, that the difference between lab and actual PHEV energy use and CO₂ output is significantly greater than for gasoline or conventional cars,” the expert stated. “All policy adjustments concerning PHEVs should be made with extreme care and considering that evidence.”