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PHEVs produce nearly five times more planet-heating pollution than official figures indicate, as per a new analysis.

Widening Discrepancy In Official and Actual CO2 Output

Data shows that PHEVs emit only one-fifth lower CO₂ than traditional gas and diesel vehicles, according to analysis conducted by a advocacy group. This contrasts sharply with laboratory estimates, which suggested a 75% reduction in emissions.

Researchers studied information from onboard energy use meters of eight hundred thousand cars registered in the EU between 2021 and 2023. They found that actual CO₂ output from PHEVs in 2023 were 4.9 times greater 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 study. “That gap is growing and poses a serious issue. As a result, PHEVs emit nearly as heavily as petrol vehicles.”

Key Reasons Behind the Discrepancy

Researchers linked the majority of the gap to inflated estimates of the “utility factor” – the ratio of kilometers driven in electric power compared to overall distance. The team determined that only 27% of driving was done in EV mode, whereas lab assumptions assumed 84%.

Even, when running in EV mode, pollution levels were significantly higher than lab estimates. This happened because electric motors were not strong enough to function alone, resulting to engines using gasoline for almost a third of the distance completed in electric mode.

Policy and Financial Implications

According to estimates, the lowballing of PHEV CO2 output allowed several large carmaker groups to avoid more than €5bn in fines between 2021 and 2023, by falsely easing compliance with European Union fleet-average CO₂ targets.

Additionally, owners of PHEVs would spend about €500 extra per year in operating expenses than is estimated under lab tests.

“The bold claims that manufacturers like to make about their plug-in hybrid vehicles are obviously far from the mark,” commented a automotive expert. “Consumers are being duped into thinking that by buying a PHEV, they are helping the planet and saving money. Actually, PHEVs are little improved than regular gas and diesel vehicles in terms of energy use, CO₂ emissions, and running expenses.”

Policy Debate and Industry Pressure

Hybrid cars have recently been brought back into policy debates as carmakers have lobbied the European Union to weaken CO₂ targets. A proposed ban on sales of new internal combustion cars in 2035 has faced intense pressure from the automotive industry and resistance from EU countries with significant automotive industries.

Some high-level officials have suggested plug-in hybrids as a possible “flexibility” option to introduce in the legislation.

One independent energy policy specialist, who was unaffiliated with the research, described the analysis a “highly valuable contribution” after years in which segments of the car industry claimed there was insufficient data to accurately evaluate real-world CO2 output.

“The results show, beyond any doubt, that the gap between lab and real-world PHEV fuel consumption and CO₂ emissions is significantly larger than for gasoline or conventional cars,” they said. “All regulatory adjustments concerning PHEVs should be made with extreme caution and in the light of this evidence.”