🔗 Share this article

PHEVs release almost five times more planet-heating emissions than lab-reported data indicate, according to a new analysis.

Growing Discrepancy In Lab and Real-World Emissions

Statistics reveals that PHEVs release only one-fifth lower CO₂ than traditional petrol and diesel vehicles, according to research conducted by a advocacy group. This differs sharply with laboratory estimates, which suggested a three-quarters decrease in emissions.

Researchers examined data from onboard energy use monitors of eight hundred thousand vehicles registered in Europe between 2021 and 2023. They found that actual CO₂ emissions from PHEVs in 2023 were nearly five times greater than lab figures, up from 3.5 times in 2021.

“Real-world CO2 output are rising, while official figures are decreasing,” said a senior analyst involved in the report. “That discrepancy is widening and creates a significant issue. Consequently, PHEVs pollute almost as much as petrol vehicles.”

Primary Reasons Driving the Discrepancy

Analysts attributed the majority of the difference to inflated estimates of the “utility factor” – the percentage of miles driven in electric mode relative to overall distance. The team found that only 27% of travel was done in electric mode, whereas lab estimates suggested over four-fifths.

Even, when running in electric mode, pollution levels were well above official projections. That occurred because electric motors were not strong sufficient to function alone, leading to combustion motors burning gasoline for almost a third of the travel covered in electric mode.

Regulatory and Economic Implications

According to estimates, the lowballing of PHEV emissions enabled several large carmaker companies to escape over €5bn in penalties from 2021 and 2023, by falsely easing adherence with EU fleet-average CO₂ targets.

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

“The strong claims that manufacturers like to make about their PHEV vehicles are obviously way off the mark,” stated a transport expert. “Buyers are being duped into thinking that by purchasing a PHEV, they are helping the planet and cutting costs. In reality, PHEVs are little improved than standard gas and diesel vehicles in terms of energy use, CO₂ production, and operating expenses.”

Political Discussion and Automotive Pressure

Hybrid vehicles have recently been drawn back into political debates as automakers have lobbied the EU to weaken CO₂ standards. A planned ban on new combustion engine cars in 2035 has faced heavy pressure from the car sector and opposition from EU countries with large car manufacturing.

Several senior officials have proposed plug-in hybrids as a potential “flexibility” solution to include in the regulation.

An independent energy economics expert, who was unaffiliated with the research, described the report a “very useful contribution” after years in which parts of the automotive sector argued there was insufficient information to accurately evaluate actual emissions.

“These findings show, without question, that the gap between official and real-world PHEV energy use and CO₂ emissions is significantly larger than for petrol or conventional cars,” the expert said. “Any policy changes concerning PHEVs should be made with extreme caution and considering that data.”