🔗 Share this article

PHEVs emit almost 5x more planet-heating emissions than lab-reported figures indicate, as per a new report.

Growing Discrepancy In Official and Actual Emissions

Data reveals that PHEVs release only one-fifth lower CO₂ than traditional petrol and diesel cars, based on research carried out by a advocacy group. That contrasts significantly with laboratory estimates, which assumed a 75% decrease in emissions.

Analysts studied information from in-vehicle fuel consumption meters of eight hundred thousand vehicles registered in the EU between 2021 and 2023. The team found that real-world CO₂ output from PHEVs in 2023 were nearly five times higher than official figures, up from 3.5 times in 2021.

“Real-world CO2 output are increasing, while lab-reported emissions are falling,” said a senior analyst participating in the report. “This gap is widening and poses a significant problem. Consequently, PHEVs pollute almost as heavily as gasoline vehicles.”

Key Factors Behind the Emissions Gap

Researchers linked most of the gap to inflated estimates of the “electric driving share” – the ratio of miles travelled in electric power compared to overall mileage. They found that just 27% of driving was done in electric mode, while lab estimates suggested 84%.

Additionally, when running in EV mode, pollution levels were significantly higher than lab projections. That occurred because EV motors were not strong enough to operate alone, resulting to engines burning gasoline for almost a third of the distance completed in electric mode.

Policy and Financial Implications

Based on calculations, the underestimation of PHEV emissions allowed several major carmaker groups to escape more than €5bn in fines from 2021 and 2023, by artificially easing adherence with European Union average fleet CO₂ standards.

Furthermore, drivers of PHEVs would pay about €500 extra per year in operating costs than would be estimated under lab conditions.

“The strong claims that automakers often promote about their plug-in hybrid cars are clearly way off the mark,” stated a automotive expert. “Buyers are being duped into believing that by purchasing a PHEV, they are benefiting the environment and cutting money. Actually, PHEVs are little better than regular gas and diesel vehicles in terms of energy use, CO₂ emissions, and running expenses.”

Policy Discussion and Automotive Pressure

Hybrid vehicles have lately been drawn again into political debates as carmakers have pressed the EU to relax CO₂ standards. A proposed prohibition on sales of new combustion engine cars in 2035 has faced heavy lobbying from the automotive industry and opposition from EU countries with large automotive industries.

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

An independent energy economics expert, who was not involved with the study, described the analysis a “very useful contribution” after a long period in which segments of the car sector claimed there was too little data to accurately assess actual emissions.

“The results demonstrate, without question, that the gap in lab and real-world PHEV energy use and CO₂ emissions is significantly larger than for gasoline or conventional vehicles,” they said. “All regulatory adjustments concerning PHEVs should be implemented with extreme care and considering this data.”