🔗 Share this article

PHEVs produce almost 5x more planet-heating pollution than lab-reported figures indicate, according to a recent analysis.

Widening Gap In Lab and Real-World Emissions

Data shows that PHEVs release just one-fifth lower CO₂ than traditional petrol and diesel vehicles, based on analysis carried out by a non-profit organization. That contrasts significantly with lab estimates, which suggested a three-quarters decrease in pollution.

Analysts studied data from in-vehicle fuel consumption meters of 800,000 cars registered in Europe between 2021 and 2023. The team discovered that actual CO₂ emissions from PHEVs in 2023 were 4.9 times higher than official figures, increased from three and a half times in 2021.

“Real-world CO2 output are increasing, while lab-reported emissions are decreasing,” stated a lead analyst involved in the study. “That discrepancy is growing and poses a serious issue. As a result, PHEVs pollute nearly as much as petrol vehicles.”

Key Reasons Behind the Discrepancy

Analysts linked the majority of the difference to inflated estimates of the “electric driving share” – the ratio of kilometers driven in battery power compared to overall distance. The team determined that just 27% of travel was completed in EV mode, whereas official estimates suggested over four-fifths.

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

Regulatory and Financial Implications

Based on estimates, the lowballing of PHEV emissions allowed several major automaker companies to avoid more than €5bn in penalties between 2021 and 2023, by artificially simplifying compliance with EU average fleet CO₂ standards.

Additionally, owners of PHEVs would pay approximately €500 more annually in running costs than would be estimated under lab tests.

“The strong statements that manufacturers often promote about their PHEV cars are clearly way off the truth,” stated a automotive analyst. “Buyers are being duped into thinking that by purchasing a PHEV, they are helping the environment and saving money. Actually, PHEVs are little better than regular gas and diesel cars in terms of energy consumption, CO₂ emissions, and operating costs.”

Policy Discussion and Automotive Pressure

Hybrid cars have recently been drawn back into policy discussions as automakers have pressed the EU to relax CO₂ targets. A planned prohibition on sales of new combustion engine vehicles in 2035 has faced heavy lobbying from the car industry and resistance from EU countries with significant car industries.

Several high-level officials have suggested PHEVs as a possible “compromise” solution to include in the regulation.

An external energy economics expert, who was unaffiliated with the study, described the report a “highly valuable contribution” after a long period in which segments of the automotive industry claimed there was insufficient data to properly evaluate real-world CO2 output.

“These findings demonstrate, without question, that the difference in lab and actual PHEV fuel consumption and CO₂ output is much, much larger than for petrol or diesel cars,” they said. “All policy adjustments regarding PHEVs should be made with utmost caution and considering that evidence.”