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PHEVs release almost five times more global warming emissions than lab-reported figures show, as per a recent report.

Widening Gap In Official and Real-World CO2 Output

Statistics shows that PHEVs release only one-fifth lower CO₂ than traditional gas and diesel cars, according to research carried out by a non-profit group. This differs sharply with laboratory tests, which suggested a three-quarters reduction in pollution.

Researchers studied information from onboard energy use monitors of eight hundred thousand cars registered in Europe from 2021 and 2023. The team discovered that real-world CO₂ output from PHEVs in 2023 were nearly five times greater than official estimates, increased from three and a half times in 2021.

“Real-world CO2 output are increasing, while lab-reported figures are decreasing,” said a lead researcher participating in the study. “That discrepancy is widening and creates a serious problem. Consequently, PHEVs emit nearly as heavily as petrol vehicles.”

Primary Factors Driving the Discrepancy

Analysts attributed most of the gap to overestimates of the “electric driving share” – the percentage of kilometers travelled in battery power compared to total distance. The team found that only a quarter of travel was completed in electric mode, whereas lab estimates assumed over four-fifths.

Additionally, when running in EV mode, emission amounts were well above lab projections. That occurred because electric motors were not strong sufficient to operate independently, resulting to engines using gasoline for nearly a third of the travel completed in EV mode.

Policy and Economic Consequences

Based on calculations, the underestimation of PHEV emissions allowed four major carmaker companies to escape more than €5bn in penalties between 2021 and 2023, by falsely easing adherence with European Union fleet-average CO₂ targets.

Additionally, drivers of PHEVs would spend about €500 more annually in running costs than would be assumed under laboratory conditions.

“The strong claims that automakers often promote about their PHEV vehicles are clearly far from the mark,” stated a automotive expert. “Buyers are being duped into thinking that by buying a PHEV, they are benefiting the planet and saving money. In reality, PHEVs are only slightly improved than regular petrol and diesel vehicles in terms of fuel consumption, CO₂ production, and running costs.”

Policy Debate and Automotive Pressure

Plug-in hybrid vehicles have lately been brought back into political discussions as carmakers have lobbied the European Union to relax CO₂ targets. A planned ban on sales of new internal combustion cars in 2035 has faced intense pressure from the car sector and opposition from member states with large automotive industries.

Some high-level politicians have proposed plug-in hybrids as a possible “flexibility” solution to include in the legislation.

One external energy policy specialist, who was unaffiliated with the study, called the analysis a “highly valuable contribution” after years in which parts of the car sector argued there was insufficient data to properly assess actual emissions.

“The results demonstrate, beyond any doubt, that the gap in official and real-world PHEV energy use and CO₂ output is much, much larger than for petrol or conventional cars,” they said. “All regulatory changes regarding PHEVs should be made with extreme caution and in the light of this evidence.”