🔗 Share this article

PHEVs release nearly 5x more global warming pollution than lab-reported figures indicate, as per a new analysis.

Growing Gap In Official and Real-World Emissions

Statistics shows that PHEVs emit just one-fifth less CO₂ than conventional gas and diesel cars, according to research carried out by a non-profit group. This contrasts significantly with laboratory tests, which assumed a 75% decrease in pollution.

Researchers examined data from onboard energy use meters of 800,000 vehicles sold in the EU between 2021 and 2023. They found that actual CO₂ output from PHEVs in 2023 were 4.9 times greater than lab estimates, up from three and a half times in 2021.

“Actual CO2 output are rising, while official figures are falling,” said a lead analyst participating in the report. “This discrepancy is growing and poses a serious problem. Consequently, PHEVs pollute almost as much as gasoline vehicles.”

Key Factors Behind the Emissions Gap

Researchers linked most of the gap to overestimates of the “utility factor” – the percentage of miles travelled in battery power relative to total mileage. They found that just 27% of travel was done in electric mode, whereas lab estimates assumed 84%.

Even, when running in electric mode, pollution levels were significantly higher than lab estimates. This happened because electric motors were insufficiently powerful sufficient to operate independently, resulting to combustion motors burning gasoline for almost a third of the distance covered in electric mode.

Regulatory and Financial Implications

Based on estimates, the underestimation of PHEV emissions enabled four major carmaker groups to escape over €5bn in penalties from 2021 and 2023, by falsely easing adherence with EU fleet-average CO₂ targets.

Additionally, owners of PHEVs could pay about €500 more annually in running expenses than is estimated under lab tests.

“The strong statements that automakers like to make about their plug-in hybrid cars are obviously far from the mark,” commented a automotive expert. “Buyers are being duped into thinking that by buying a PHEV, they are benefiting the planet and cutting costs. Actually, PHEVs are only slightly better than regular petrol and diesel cars in terms of fuel use, CO₂ emissions, and operating costs.”

Political Debate and Automotive Lobbying

Plug-in hybrid vehicles have recently been brought back into political discussions as automakers have lobbied the European Union to relax CO₂ targets. A proposed prohibition on new internal combustion vehicles in 2035 has faced intense lobbying from the automotive industry and resistance from member states with large automotive industries.

Some senior officials have proposed plug-in hybrids as a potential “flexibility” solution to include in the legislation.

One external energy economics expert, who was not involved with the study, called the report a “highly valuable addition” after a long period in which segments of the automotive sector claimed there was insufficient data to accurately evaluate actual CO2 output.

“The results show, beyond any doubt, that the difference between lab and real-world PHEV energy use and CO₂ output is much, much larger than for gasoline or diesel cars,” the expert stated. “Any regulatory changes regarding PHEVs should be made with utmost caution and considering this evidence.”