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PHEVs release nearly five times more global warming pollution than lab-reported data indicate, as per a recent report.

Growing Discrepancy Between Official and Actual Emissions

Statistics reveals that PHEVs release just one-fifth lower CO₂ than conventional gas and diesel cars, based on research conducted by a advocacy group. This contrasts sharply with lab estimates, which assumed a 75% decrease in pollution.

Analysts examined information from onboard fuel consumption meters of 800,000 vehicles sold in the EU from 2021 and 2023. The team found that real-world CO₂ output from PHEVs in 2023 were 4.9 times higher than official estimates, increased from 3.5 times in 2021.

“Real-world CO2 output are rising, while lab-reported emissions are decreasing,” stated a lead analyst involved in the study. “This gap is widening and poses a significant problem. As a result, PHEVs pollute nearly as heavily as petrol cars.”

Key Factors Driving the Emissions Gap

Researchers linked the majority of the gap to inflated estimates of the “electric driving share” – the ratio of kilometers travelled in electric power compared to overall mileage. They determined that just 27% of travel was done in EV mode, whereas official estimates suggested 84%.

Additionally, when operating in electric mode, emission amounts were significantly higher than lab projections. This occurred because EV motors were insufficiently powerful enough to operate alone, leading to combustion motors burning fossil fuels for nearly one-third of the distance completed in electric mode.

Regulatory and Financial Consequences

Based on calculations, the underestimation of PHEV CO2 output enabled four large carmaker groups to escape more than €5bn in penalties from 2021 and 2023, by falsely easing adherence with EU average fleet CO₂ standards.

Furthermore, drivers of PHEVs would spend about €500 more per year in operating expenses than is estimated under laboratory tests.

“The strong statements that manufacturers like to make about their plug-in hybrid cars are clearly way off the truth,” commented a transport expert. “Consumers are being misled into believing that by buying a PHEV, they are helping the planet and cutting money. In reality, PHEVs are little improved than standard petrol and diesel cars in terms of energy use, CO₂ emissions, and operating expenses.”

Policy Discussion and Industry Lobbying

Plug-in hybrid cars have recently been drawn back into political discussions as carmakers have pressed the EU to relax CO₂ standards. A planned prohibition on sales of new combustion engine vehicles in 2035 has faced heavy pressure from the automotive sector and opposition from member states with large car industries.

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

An external energy policy expert, who was not involved with the study, called the report a “highly valuable addition” after a long period in which parts of the automotive industry claimed there was too little information to accurately evaluate actual emissions.

“These findings demonstrate, without question, that the gap between lab and real-world PHEV energy use and CO₂ output is much, much larger than for gasoline or diesel vehicles,” the expert said. “Any policy changes regarding PHEVs should be made with utmost care and considering that evidence.”