🔗 Share this article

Plug-in hybrid electric vehicles produce almost 5x greater planet-heating emissions than lab-reported figures indicate, according to a recent analysis.

Widening Gap In Official and Actual Emissions

Statistics shows that PHEVs release only 19% lower CO₂ than conventional petrol and diesel cars, according to research conducted by a advocacy organization. That contrasts sharply with laboratory tests, which assumed a three-quarters decrease in pollution.

Researchers examined data from in-vehicle energy use monitors of 800,000 vehicles sold in the EU between 2021 and 2023. The team discovered that actual CO₂ emissions from PHEVs in 2023 were nearly five times greater than official estimates, increased from three and a half times in 2021.

“Actual CO2 output are rising, while official figures are falling,” stated a lead analyst involved in the study. “That gap is growing and creates a significant problem. Consequently, PHEVs pollute almost as much as gasoline cars.”

Key Reasons Driving the Emissions Gap

Analysts attributed the majority of the difference to inflated estimates of the “utility factor” – the ratio of miles travelled in battery power relative to total distance. They found that only a quarter of driving was done in EV mode, while official assumptions assumed 84%.

Even, when operating in electric mode, emission levels were significantly higher than lab projections. This happened because electric motors were insufficiently powerful sufficient to operate independently, resulting to engines burning gasoline for almost one-third of the distance covered in electric mode.

Policy and Financial Implications

According to estimates, the lowballing of PHEV emissions allowed several major automaker groups to escape over €5bn in penalties from 2021 and 2023, by falsely simplifying adherence with European Union average fleet CO₂ targets.

Additionally, drivers of PHEVs would spend about €500 more per year in operating expenses than is estimated under laboratory tests.

“The bold claims that manufacturers like to make about their PHEV vehicles are clearly way off the truth,” stated a automotive expert. “Buyers are being misled into believing that by purchasing a PHEV, they are benefiting the environment and cutting costs. Actually, PHEVs are little improved than regular gas and diesel vehicles in terms of energy consumption, CO₂ production, and running costs.”

Political Debate and Automotive Pressure

Hybrid vehicles have recently been brought back into policy discussions as carmakers have pressed the European Union to weaken CO₂ standards. A proposed ban on new combustion engine vehicles in 2035 has faced intense pressure from the automotive industry and opposition from member states with significant automotive manufacturing.

Some senior politicians have suggested plug-in hybrids as a potential “compromise” option to include in the legislation.

An external energy economics expert, who was not involved with the research, called the analysis a “highly valuable contribution” after a long period in which segments of the automotive sector claimed there was insufficient information to properly evaluate actual CO2 output.

“These findings show, without question, that the difference in lab and actual PHEV energy use and CO₂ emissions is much, much larger than for gasoline or diesel cars,” the expert said. “Any regulatory adjustments concerning PHEVs should be implemented with utmost care and in the light of this evidence.”