Plug-in Hybrid Vehicles Pollute Nearly as Much as Petrol Vehicles, Report Reveals

Plug-in hybrid electric vehicles release almost five times greater planet-heating pollution than lab-reported data show, as per a new report.

Growing Discrepancy Between Lab and Real-World Emissions

Statistics shows that PHEVs emit just one-fifth less CO₂ than traditional petrol and diesel cars, according to research conducted by a advocacy group. This contrasts significantly with laboratory tests, which assumed a 75% reduction in pollution.

Analysts examined information from onboard fuel consumption monitors of eight hundred thousand vehicles sold in the EU from 2021 and 2023. They discovered that actual CO₂ emissions from PHEVs in 2023 were nearly five times greater than lab figures, up from 3.5 times in 2021.

“Actual CO2 output are rising, while official figures are decreasing,” stated a senior researcher involved in the report. “This gap is growing and poses a serious problem. As a result, PHEVs pollute almost as heavily as petrol cars.”

Key Reasons Behind the Emissions Gap

Researchers linked the majority of the difference to inflated estimates of the “electric driving share” – the ratio of miles travelled in battery mode relative to total mileage. The team determined that just 27% of driving was completed in electric mode, whereas lab assumptions suggested over four-fifths.

Even, when running in electric mode, pollution levels were well above official projections. That happened because electric motors were insufficiently powerful enough to function independently, leading to combustion motors using gasoline for nearly one-third of the distance completed in EV mode.

Policy and Financial Implications

Based on estimates, the underestimation of PHEV CO2 output allowed four large automaker groups to avoid more than €5bn in penalties from 2021 and 2023, by artificially simplifying compliance with European Union average fleet CO₂ standards.

Furthermore, owners of PHEVs would pay about €500 extra annually in running expenses than is assumed under lab conditions.

“The bold statements that manufacturers often promote about their PHEV cars are clearly far from the truth,” stated a automotive expert. “Buyers are being duped into thinking that by buying a PHEV, they are helping the planet and saving money. Actually, PHEVs are little better than standard petrol and diesel cars in terms of fuel consumption, CO₂ production, and operating expenses.”

Policy Debate and Industry Pressure

Plug-in hybrid vehicles have lately been drawn again into political discussions as carmakers have pressed the EU to relax CO₂ targets. A planned prohibition on new internal combustion cars in 2035 has faced intense lobbying from the car industry and resistance from EU countries with large car industries.

Some high-level politicians have proposed PHEVs as a potential “flexibility” solution to include in the regulation.

One external energy economics specialist, who was not involved with the research, called the analysis a “highly valuable contribution” after a long period in which parts of the car industry claimed there was insufficient data to accurately assess actual CO2 output.

“The results demonstrate, beyond any doubt, that the difference between official and real-world PHEV energy use and CO₂ output is much, much greater than for petrol or diesel cars,” they said. “Any regulatory adjustments concerning PHEVs should be made with utmost caution and considering that evidence.”