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PHEVs release almost 5x greater global warming emissions than lab-reported figures show, as per a recent report.

Growing Discrepancy In Lab and Real-World CO2 Output

Data shows that PHEVs release only one-fifth lower CO₂ than conventional petrol and diesel cars, according to research conducted by a advocacy organization. This contrasts significantly with lab tests, which assumed a three-quarters decrease in emissions.

Analysts examined information from onboard energy use meters of eight hundred thousand cars sold in Europe between 2021 and 2023. They discovered that actual CO₂ emissions from PHEVs in 2023 were 4.9 times higher than lab figures, up from three and a half times in 2021.

“Actual emissions are increasing, while lab-reported emissions are falling,” said a senior researcher involved in the report. “That gap is growing and creates a significant problem. As a result, PHEVs emit almost as heavily as petrol cars.”

Primary Factors Behind the Emissions Gap

Researchers linked the majority of the difference to inflated estimates of the “electric driving share” – the ratio of kilometers driven in battery mode compared to overall mileage. They determined that only 27% of travel was done in electric mode, while lab estimates assumed over four-fifths.

Even, when operating in electric mode, pollution levels were significantly higher than lab estimates. This happened because EV motors were not strong enough to operate alone, leading to engines burning gasoline for almost a third of the distance covered in EV mode.

Regulatory and Economic Implications

Based on calculations, the underestimation of PHEV CO2 output allowed several major carmaker groups to escape over €5bn in penalties between 2021 and 2023, by artificially simplifying adherence with European Union average fleet CO₂ standards.

Furthermore, drivers of PHEVs could spend about €500 extra per year in running costs than is assumed under laboratory conditions.

“The strong statements that automakers often promote about their plug-in hybrid cars are obviously far from the truth,” commented a automotive analyst. “Buyers are being duped into thinking that by purchasing a PHEV, they are benefiting the environment and cutting costs. In reality, PHEVs are little better than regular gas and diesel cars in terms of energy use, CO₂ emissions, and operating costs.”

Political Debate and Industry Pressure

Plug-in hybrid vehicles have lately been brought back into policy debates as carmakers have lobbied the European Union to weaken CO₂ targets. A planned prohibition on sales of new internal combustion vehicles in 2035 has faced intense lobbying from the car industry and opposition from EU countries with large automotive manufacturing.

Some high-level politicians have proposed PHEVs as a potential “compromise” option to include in the regulation.

An external energy economics expert, who was not involved with the research, called the analysis a “highly valuable addition” after years in which segments of the car sector claimed there was insufficient information to properly assess actual emissions.

“These findings demonstrate, beyond any doubt, that the difference between official and real-world PHEV energy use and CO₂ emissions is significantly greater than for petrol or conventional vehicles,” they said. “Any regulatory changes regarding PHEVs should be implemented with extreme care and in the light of that data.”