Plug in Hybrid electric Vehicles Emit Almost as Heavily as Gasoline Vehicles, Study Finds

Plug-in hybrid cars emit almost five times more global warming emissions than official data indicate, according to a recent analysis.

Widening Gap Between Lab and Actual CO2 Output

Statistics shows that PHEVs emit only 19% less CO₂ than conventional gas and diesel cars, according to analysis carried out by a non-profit organization. That differs significantly with lab estimates, which assumed a 75% reduction in emissions.

Researchers studied information from in-vehicle fuel consumption meters of eight hundred thousand cars sold in Europe between 2021 and 2023. The team discovered that real-world CO₂ emissions from PHEVs in 2023 were nearly five times higher than official figures, increased from 3.5 times in 2021.

“Actual emissions are increasing, while lab-reported figures are falling,” stated a senior analyst participating in the report. “That discrepancy is growing and creates a serious issue. As a result, PHEVs emit almost as much as gasoline cars.”

Primary Reasons Driving the Discrepancy

Analysts attributed most of the difference to overestimates of the “electric driving share” – the ratio of miles travelled in battery mode compared to total distance. The team found that just a quarter of travel was completed in electric mode, whereas official assumptions suggested 84%.

Even, when operating in EV mode, pollution amounts were significantly higher than lab projections. This happened because EV motors were insufficiently powerful enough to operate alone, resulting to combustion motors using gasoline for nearly one-third of the travel covered in EV mode.

Regulatory and Economic Consequences

Based on calculations, the underestimation of PHEV CO2 output enabled several major automaker companies to avoid over €5bn in penalties between 2021 and 2023, by falsely easing compliance with EU fleet-average CO₂ targets.

Furthermore, drivers of PHEVs could pay approximately €500 more per year in running costs than is estimated under lab tests.

“The bold statements that manufacturers like to make about their plug-in hybrid vehicles are clearly far from the mark,” stated a automotive analyst. “Consumers are being duped into thinking that by purchasing a PHEV, they are helping the planet and cutting costs. Actually, PHEVs are only slightly improved than regular petrol and diesel vehicles in terms of fuel consumption, CO₂ production, and operating costs.”

Policy Discussion and Automotive Pressure

Hybrid cars have lately been brought back into political discussions as carmakers have pressed the European Union to relax CO₂ targets. A planned prohibition on new combustion engine cars in 2035 has faced intense lobbying from the car sector and resistance from member states with large automotive industries.

Some high-level politicians have suggested PHEVs as a potential “compromise” solution to introduce in the regulation.

One external energy economics specialist, who was not involved with the study, called the analysis a “highly valuable addition” after years in which parts of the automotive sector argued there was insufficient information to properly assess real-world emissions.

“These findings show, beyond any doubt, that the gap between lab and real-world PHEV energy use and CO₂ output is much, much greater than for petrol or conventional vehicles,” they stated. “Any policy adjustments concerning PHEVs should be made with extreme care and in the light of that evidence.”