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PHEVs release almost 5x more global warming emissions than lab-reported data show, as per a recent analysis.

Widening Gap In Official and Real-World CO2 Output

Statistics reveals that PHEVs release only one-fifth lower CO₂ than conventional gas and diesel cars, based on analysis carried out by a advocacy group. That contrasts significantly with lab tests, which suggested a 75% reduction in pollution.

Researchers examined data from onboard energy use monitors of eight hundred thousand cars sold in the EU from 2021 and 2023. They found that real-world CO₂ output from PHEVs in 2023 were 4.9 times higher than lab figures, up from 3.5 times in 2021.

“Real-world CO2 output are rising, while lab-reported emissions are decreasing,” stated a senior researcher involved in the study. “That gap is widening and poses a serious problem. As a result, PHEVs pollute nearly as much as gasoline cars.”

Primary Reasons Behind the Emissions Gap

Analysts attributed most of the difference to overestimates of the “utility factor” – the percentage of miles driven in electric power relative to total distance. They found that only 27% of travel was completed in electric mode, whereas lab estimates assumed 84%.

Additionally, when operating in EV mode, emission amounts were well above lab projections. That happened because electric motors were not strong enough to function alone, resulting to combustion motors using gasoline for almost one-third of the distance completed in EV mode.

Regulatory and Financial Implications

According to calculations, the underestimation of PHEV CO2 output enabled four major automaker groups to escape over €5bn in penalties from 2021 and 2023, by artificially easing compliance with European Union average fleet CO₂ targets.

Additionally, drivers of PHEVs would spend about €500 more annually in operating expenses than would be assumed under lab conditions.

“The bold claims that manufacturers often promote about their plug-in hybrid vehicles are obviously far from the mark,” stated a transport analyst. “Buyers are being misled into believing that by buying a PHEV, they are benefiting the planet and saving money. In reality, PHEVs are little improved than standard petrol and diesel vehicles in terms of energy use, CO₂ production, and operating costs.”

Policy Debate and Automotive Pressure

Hybrid cars have recently been brought back into policy debates 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 heavy pressure from the car sector and opposition from EU countries with large car manufacturing.

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

One independent energy policy expert, who was not involved with the study, called the analysis a “highly valuable contribution” after a long period in which parts of the automotive sector argued there was insufficient information to accurately evaluate actual CO2 output.

“These findings show, without question, that the difference between official and actual PHEV energy use and CO₂ emissions is significantly larger than for gasoline or conventional cars,” the expert said. “Any regulatory changes concerning PHEVs should be made with extreme caution and considering this data.”