🔗 Share this article

PHEVs produce nearly 5x more global warming emissions than official data show, according to a recent analysis.

Growing Gap Between Official and Real-World Emissions

Data shows that PHEVs release just one-fifth less CO₂ than conventional petrol and diesel vehicles, according to analysis conducted by a advocacy organization. That differs sharply with lab estimates, which assumed a 75% reduction in emissions.

Analysts examined data from in-vehicle energy use monitors of eight hundred thousand vehicles sold in Europe between 2021 and 2023. The team discovered that actual CO₂ output from PHEVs in 2023 were 4.9 times higher than lab estimates, increased from 3.5 times in 2021.

“Actual CO2 output are increasing, while lab-reported emissions are falling,” stated a senior researcher participating in the report. “That gap is widening and creates a serious problem. As a result, PHEVs pollute almost as heavily as gasoline cars.”

Key Factors Driving the Emissions Gap

Researchers linked most of the gap to overestimates of the “electric driving share” – the ratio of kilometers travelled in battery mode relative to overall distance. The team determined that just a quarter of travel was done in EV mode, while lab assumptions assumed over four-fifths.

Additionally, when running in EV mode, emission amounts were significantly higher than lab estimates. That occurred because electric motors were not strong enough to function independently, leading to combustion motors using fossil fuels for almost one-third of the distance covered in EV mode.

Regulatory and Financial Implications

According to estimates, the lowballing of PHEV emissions allowed several large carmaker companies to escape over €5bn in fines from 2021 and 2023, by artificially simplifying adherence with European Union average fleet CO₂ targets.

Furthermore, owners of PHEVs would spend approximately €500 extra annually in operating expenses than would be estimated under lab conditions.

“The bold statements that automakers often promote about their plug-in hybrid vehicles are clearly far from the mark,” stated a automotive expert. “Consumers are being misled into believing that by purchasing a PHEV, they are helping the environment and saving costs. In reality, PHEVs are little improved than regular gas and diesel cars in terms of energy consumption, CO₂ production, and operating costs.”

Political Debate and Industry Pressure

Hybrid vehicles have recently been brought back into policy debates as carmakers have pressed the EU to weaken CO₂ standards. A proposed ban on sales of new combustion engine cars in 2035 has faced intense pressure from the car sector and resistance from member states with large car industries.

Several senior politicians have suggested plug-in hybrids as a possible “compromise” solution to introduce in the regulation.

An independent energy economics specialist, who was unaffiliated with the study, called the report a “highly valuable contribution” after years in which parts of the car sector claimed there was too little data to properly assess actual emissions.

“The results demonstrate, without question, that the difference between lab and real-world PHEV energy use and CO₂ output is much, much greater than for petrol or conventional cars,” they stated. “All regulatory changes regarding PHEVs should be implemented with utmost care and considering this data.”