🔗 Share this article

PHEVs produce almost five times greater planet-heating pollution than lab-reported data indicate, as per a new analysis.

Widening Discrepancy In Official and Real-World CO2 Output

Statistics reveals that PHEVs emit only 19% lower CO₂ than conventional petrol and diesel cars, according to research conducted by a non-profit group. That contrasts significantly with laboratory tests, which suggested a three-quarters reduction in emissions.

Researchers examined data from in-vehicle energy use meters of eight hundred thousand vehicles registered in the EU from 2021 and 2023. The team discovered that real-world CO₂ output from PHEVs in 2023 were nearly five times greater than lab figures, increased from 3.5 times in 2021.

“Actual CO2 output are increasing, while official figures are decreasing,” stated a lead analyst involved in the study. “This discrepancy is growing and creates a significant problem. Consequently, PHEVs pollute almost as heavily as gasoline cars.”

Key Reasons Driving the Discrepancy

Analysts linked the majority of the difference to overestimates of the “utility factor” – the percentage of kilometers driven in battery mode compared to overall distance. The team determined that just 27% of travel was completed in electric mode, whereas official estimates suggested over four-fifths.

Additionally, when running in electric mode, emission amounts were well above official projections. That happened because electric motors were insufficiently powerful enough to function alone, leading to combustion motors using fossil fuels for nearly one-third of the distance covered in electric mode.

Policy and Financial Consequences

Based on calculations, the underestimation of PHEV emissions allowed four large automaker companies to avoid more than €5bn in fines from 2021 and 2023, by falsely simplifying adherence with EU fleet-average CO₂ standards.

Furthermore, owners of PHEVs would spend approximately €500 more annually in operating expenses than is assumed under lab conditions.

“The bold statements that manufacturers often promote about their PHEV cars are clearly far from the truth,” commented a transport expert. “Buyers are being misled into thinking that by buying a PHEV, they are helping the environment and saving costs. Actually, PHEVs are only slightly improved than regular petrol and diesel vehicles in terms of energy use, CO₂ emissions, and running costs.”

Political Discussion and Industry Lobbying

Plug-in hybrid vehicles have lately been drawn back into political debates as automakers have lobbied the European Union to relax CO₂ standards. A planned prohibition on new internal combustion cars in 2035 has faced intense pressure from the car sector and opposition from member states with significant car industries.

Some senior politicians have proposed PHEVs as a possible “flexibility” solution to include in the legislation.

One external energy policy expert, who was unaffiliated with the research, called the report a “highly valuable addition” after years in which segments of the car sector argued there was insufficient data to accurately evaluate real-world emissions.

“The results show, without question, that the difference in official and real-world PHEV fuel consumption and CO₂ emissions is much, much larger than for gasoline or conventional cars,” they said. “Any policy changes concerning PHEVs should be implemented with utmost care and considering that evidence.”