🔗 Share this article

Plug-in hybrid cars release almost five times greater planet-heating pollution than official data indicate, as per a new report.

Growing Gap In Official and Real-World CO2 Output

Data reveals that PHEVs release only one-fifth lower CO₂ than conventional petrol and diesel cars, according to analysis conducted by a non-profit group. That contrasts significantly with lab tests, which assumed a three-quarters reduction in emissions.

Analysts examined information from in-vehicle fuel consumption meters of eight hundred thousand cars registered in the EU from 2021 and 2023. They found that real-world CO₂ emissions from PHEVs in 2023 were nearly five times higher than lab estimates, increased from 3.5 times in 2021.

“Real-world CO2 output are increasing, while official figures are decreasing,” said a senior analyst involved in the report. “That gap is widening and poses a serious issue. As a result, PHEVs pollute nearly as heavily as petrol vehicles.”

Key Reasons Behind the Discrepancy

Analysts attributed the majority of the difference to inflated estimates of the “utility factor” – the ratio of miles driven in battery power compared to overall distance. The team found that only 27% of driving was completed in EV mode, whereas official estimates suggested over four-fifths.

Even, when operating in EV mode, pollution amounts were well above official estimates. That occurred because electric motors were not strong sufficient to function independently, resulting to engines using fossil fuels for almost one-third of the distance covered in electric mode.

Regulatory and Financial Implications

Based on calculations, the underestimation of PHEV emissions allowed several large carmaker groups to avoid more than €5bn in penalties from 2021 and 2023, by falsely easing adherence with EU fleet-average CO₂ targets.

Furthermore, drivers of PHEVs would spend about €500 more per year in operating costs than would be assumed under laboratory conditions.

“The bold claims that manufacturers often promote about their PHEV cars are obviously way off the mark,” stated a automotive analyst. “Consumers are being duped into believing that by purchasing a PHEV, they are benefiting the planet and cutting money. Actually, PHEVs are only slightly improved than standard gas and diesel vehicles in terms of fuel use, CO₂ production, and operating expenses.”

Political Discussion and Industry Pressure

Plug-in hybrid cars have lately been brought again into political discussions as carmakers have pressed the European Union to relax CO₂ targets. A planned prohibition on new combustion engine cars in 2035 has faced intense pressure from the car sector and opposition from member states with significant car industries.

Several senior officials have suggested PHEVs as a potential “compromise” option to include in the legislation.

An external energy policy expert, who was not involved with the study, called the analysis a “highly valuable addition” after a long period in which parts of the car sector claimed there was insufficient data to accurately evaluate actual emissions.

“The results show, without question, that the difference between official and actual PHEV fuel consumption and CO₂ output is significantly greater than for petrol or diesel vehicles,” the expert said. “All policy changes regarding PHEVs should be made with extreme care and in the light of this data.”