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PHEVs emit almost five times greater global warming emissions than official data show, as per a recent analysis.

Growing Gap Between Lab and Actual CO2 Output

Statistics reveals that PHEVs release just one-fifth lower CO₂ than traditional petrol and diesel vehicles, based on research carried out by a advocacy group. This differs sharply with lab estimates, which assumed a 75% decrease in emissions.

Analysts studied data from onboard energy use meters of 800,000 vehicles registered in Europe from 2021 and 2023. The team found that real-world CO₂ emissions from PHEVs in 2023 were 4.9 times higher than official estimates, up from three and a half times in 2021.

“Actual emissions are rising, while lab-reported figures are decreasing,” said a senior analyst involved in the study. “This gap is growing and poses a significant issue. As a result, PHEVs emit nearly as heavily as gasoline cars.”

Primary Factors Behind the Discrepancy

Researchers attributed most of the gap to inflated estimates of the “utility factor” – the percentage of kilometers travelled in battery power compared to overall mileage. They found that just a quarter of driving was done in electric mode, whereas lab estimates suggested over four-fifths.

Even, when running in EV mode, pollution amounts were well above official estimates. This happened because electric motors were insufficiently powerful enough to function alone, resulting to engines using gasoline for almost one-third of the distance covered in electric mode.

Regulatory and Financial Implications

According to estimates, the underestimation of PHEV emissions enabled several large carmaker groups to escape more than €5bn in penalties between 2021 and 2023, by artificially simplifying adherence with EU fleet-average CO₂ standards.

Additionally, owners of PHEVs could pay approximately €500 more annually in running costs than is assumed under lab conditions.

“The bold claims that manufacturers often promote about their plug-in hybrid vehicles are clearly way off the truth,” commented a automotive expert. “Buyers are being misled into thinking that by purchasing a PHEV, they are benefiting the environment and cutting costs. In reality, PHEVs are little improved than standard petrol and diesel cars in terms of fuel use, CO₂ production, and running expenses.”

Political Discussion and Automotive Lobbying

Hybrid vehicles have lately been brought again into policy discussions as carmakers have pressed the EU to relax CO₂ standards. A planned ban on new combustion engine cars in 2035 has faced heavy lobbying from the car sector and resistance from member states with significant automotive manufacturing.

Several high-level politicians have proposed plug-in hybrids as a possible “compromise” solution to include in the regulation.

An external energy economics expert, who was not involved with the research, called the report a “very useful contribution” after years in which parts of the automotive sector argued there was too little information to accurately assess real-world CO2 output.

“These findings show, without question, that the difference in official and real-world PHEV energy use and CO₂ emissions is much, much larger than for gasoline or conventional cars,” the expert stated. “All policy adjustments concerning PHEVs should be implemented with extreme caution and in the light of this evidence.”