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Plug-in hybrid cars release almost five times greater global warming pollution than official data indicate, as per a recent analysis.

Growing Gap In Lab and Actual Emissions

Statistics shows that PHEVs emit only 19% less CO₂ than conventional petrol and diesel vehicles, according to analysis conducted by a advocacy group. That contrasts sharply with lab tests, which suggested a three-quarters reduction in emissions.

Analysts examined data from in-vehicle fuel consumption monitors of 800,000 cars sold in the EU between 2021 and 2023. They found that actual CO₂ emissions from PHEVs in 2023 were 4.9 times greater than official figures, up from 3.5 times in 2021.

“Actual emissions are increasing, while official figures are decreasing,” said a lead researcher participating in the study. “That discrepancy is widening and poses a serious issue. As a result, PHEVs emit almost as much as gasoline cars.”

Key Reasons Behind the Discrepancy

Researchers linked most of the gap to inflated estimates of the “utility factor” – the percentage of kilometers travelled in battery power relative to total distance. They determined that only a quarter of driving was completed in EV mode, whereas official estimates suggested 84%.

Even, when running in electric mode, pollution amounts were significantly higher than lab projections. This occurred because EV motors were not strong enough to operate independently, resulting to combustion motors using gasoline for nearly one-third of the distance completed in electric mode.

Policy and Financial Implications

According to calculations, the lowballing of PHEV CO2 output enabled several large automaker groups to avoid more than €5bn in penalties between 2021 and 2023, by falsely simplifying compliance with EU average fleet CO₂ standards.

Furthermore, owners of PHEVs would spend about €500 more annually in running costs than is estimated under laboratory conditions.

“The bold statements that manufacturers often promote about their PHEV vehicles are clearly way off the mark,” stated a automotive expert. “Buyers are being duped into thinking that by buying a PHEV, they are helping the planet and cutting money. In reality, PHEVs are only slightly improved than regular gas and diesel cars in terms of energy consumption, CO₂ production, and running costs.”

Political Discussion and Automotive Pressure

Hybrid cars have recently been drawn back into political discussions as automakers have pressed the EU to relax CO₂ targets. A planned prohibition on new internal combustion vehicles in 2035 has faced heavy lobbying from the car sector and resistance from EU countries with large automotive industries.

Several senior politicians have proposed PHEVs as a potential “compromise” solution to include in the legislation.

An external energy policy expert, who was not involved with the research, described the report a “very useful contribution” after years in which parts of the car sector argued there was insufficient information to accurately evaluate real-world emissions.

“The results demonstrate, without question, that the difference in lab and actual PHEV energy use and CO₂ emissions is significantly greater than for petrol or diesel vehicles,” the expert said. “Any regulatory adjustments concerning PHEVs should be implemented with utmost care and in the light of that evidence.”