Plug-in Hybrid electric Cars Pollute Nearly as Heavily as Petrol Vehicles, Study Reveals

Plug-in hybrid electric vehicles emit nearly five times greater global warming pollution than official data indicate, as per a new analysis.

Widening Discrepancy In Official and Real-World CO2 Output

Statistics shows that PHEVs emit just one-fifth less CO₂ than conventional gas and diesel vehicles, based on analysis conducted by a advocacy organization. That differs significantly with lab estimates, which assumed a 75% reduction in pollution.

Analysts studied information from onboard energy use monitors of 800,000 vehicles registered in the EU from 2021 and 2023. The team found that actual CO₂ output from PHEVs in 2023 were 4.9 times greater than official estimates, increased from three and a half times in 2021.

“Actual CO2 output are increasing, while official emissions are decreasing,” said a senior researcher involved in the study. “That gap is growing and creates a significant problem. Consequently, PHEVs pollute nearly as heavily as gasoline cars.”

Key Reasons Behind the Discrepancy

Researchers attributed most of the difference to inflated estimates of the “electric driving share” – the ratio of kilometers travelled in battery power compared to overall distance. They determined that just 27% of driving was completed in electric mode, whereas lab estimates suggested 84%.

Additionally, when running in electric mode, emission levels were significantly higher than lab estimates. This happened because electric motors were insufficiently powerful sufficient to function alone, resulting to combustion motors using gasoline for almost one-third of the distance covered in electric mode.

Policy and Economic Implications

Based on estimates, the underestimation of PHEV emissions allowed several large automaker companies to escape more than €5bn in penalties from 2021 and 2023, by artificially easing adherence with EU fleet-average CO₂ targets.

Furthermore, owners of PHEVs would pay approximately €500 more per year in running expenses than would be estimated under laboratory conditions.

“The bold statements that automakers like to make about their PHEV cars are obviously far from the mark,” commented a automotive expert. “Consumers are being duped into thinking that by buying a PHEV, they are helping the planet and cutting money. Actually, PHEVs are only slightly improved than standard petrol and diesel vehicles in terms of energy consumption, CO₂ production, and running expenses.”

Political Debate and Automotive Pressure

Hybrid cars have lately been drawn again into policy debates as automakers have pressed the EU to relax CO₂ targets. A proposed ban on new internal combustion vehicles in 2035 has faced intense lobbying from the car industry and opposition from EU countries with large automotive industries.

Several high-level officials have proposed PHEVs as a possible “flexibility” solution to include in the legislation.

An independent energy economics expert, who was unaffiliated with the study, called the analysis a “very useful addition” after a long period in which parts of the automotive industry argued there was too little data to properly evaluate actual CO2 output.

“The results demonstrate, without question, that the difference between official and actual PHEV fuel consumption and CO₂ output is much, much larger than for petrol or diesel vehicles,” the expert said. “All regulatory adjustments concerning PHEVs should be made with utmost care and considering this evidence.”