🔗 Share this article

Plug-in hybrid cars release nearly five times greater planet-heating emissions than official figures show, as per a recent report.

Widening Gap In Official and Actual Emissions

Statistics reveals that PHEVs emit only 19% lower CO₂ than traditional petrol and diesel cars, according to analysis carried out by a advocacy group. That differs significantly with laboratory tests, which assumed a three-quarters decrease in pollution.

Analysts studied data from onboard fuel consumption monitors of eight hundred thousand cars sold in the EU from 2021 and 2023. They discovered that real-world CO₂ output from PHEVs in 2023 were nearly five times greater than official estimates, increased from 3.5 times in 2021.

“Actual CO2 output are rising, while lab-reported emissions are falling,” stated a senior analyst participating in the study. “This gap is growing and poses a significant problem. As a result, PHEVs emit almost as heavily as gasoline cars.”

Primary Factors Driving the Discrepancy

Researchers attributed most of the gap to overestimates of the “electric driving share” – the ratio of kilometers travelled in electric mode compared to overall distance. They determined that only 27% of driving was done in electric mode, whereas official assumptions suggested 84%.

Even, when running in EV mode, pollution levels were significantly higher than lab estimates. That occurred because electric motors were not strong enough to function alone, leading to engines using gasoline for nearly one-third of the distance covered in electric mode.

Policy and Economic Implications

According to estimates, the underestimation of PHEV emissions allowed several large automaker groups to escape more than €5bn in penalties from 2021 and 2023, by artificially easing compliance with European Union fleet-average CO₂ targets.

Additionally, owners of PHEVs could pay approximately €500 more per year in running expenses than is estimated under laboratory conditions.

“The strong claims that manufacturers like to make about their PHEV cars are obviously way off the truth,” stated a automotive analyst. “Consumers are being duped into thinking that by buying a PHEV, they are benefiting the environment and saving costs. In reality, PHEVs are only slightly better than standard petrol and diesel vehicles in terms of energy use, CO₂ emissions, and operating costs.”

Political Discussion and Industry Pressure

Plug-in hybrid vehicles have recently been brought back into political discussions as carmakers have lobbied the EU to relax CO₂ standards. A planned ban on sales of new internal combustion vehicles in 2035 has faced heavy pressure from the automotive industry and opposition from member states with significant car industries.

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

An independent energy economics expert, who was not involved with the research, called the report a “very useful addition” after years in which segments of the automotive industry argued there was too little information to accurately assess real-world CO2 output.

“The results show, beyond any doubt, that the difference between lab and actual PHEV fuel consumption and CO₂ output is much, much larger than for gasoline or conventional vehicles,” the expert stated. “All regulatory adjustments concerning PHEVs should be made with utmost caution and in the light of this data.”