Plug in Hybrid Cars Emit Almost as Heavily as Gasoline Cars, Report Finds

PHEVs release almost five times more planet-heating emissions than lab-reported figures indicate, as per a recent analysis.

Growing Discrepancy In Lab and Real-World CO2 Output

Data shows that PHEVs emit only one-fifth lower CO₂ than traditional petrol and diesel cars, according to analysis carried out by a advocacy organization. This contrasts sharply with lab estimates, which assumed a three-quarters decrease in pollution.

Analysts examined information from onboard energy use meters of 800,000 vehicles sold in Europe from 2021 and 2023. They discovered that actual CO₂ output from PHEVs in 2023 were nearly five times greater than official estimates, increased from 3.5 times in 2021.

“Real-world CO2 output are rising, while official figures are decreasing,” stated a senior analyst involved in the report. “This discrepancy is growing and poses a serious problem. Consequently, PHEVs emit nearly as heavily as gasoline cars.”

Primary Reasons Behind the Emissions Gap

Analysts attributed most of the gap to inflated estimates of the “utility factor” – the ratio of kilometers driven in electric power compared to total distance. The team determined that just 27% of travel was completed in electric mode, while official assumptions suggested 84%.

Additionally, when running in electric mode, emission amounts were significantly higher than official estimates. That occurred because EV motors were insufficiently powerful enough to operate alone, resulting to combustion motors burning fossil fuels for nearly a third of the travel completed in electric mode.

Regulatory and Financial Consequences

Based on estimates, the underestimation of PHEV CO2 output enabled several major automaker groups to avoid over €5bn in fines between 2021 and 2023, by falsely simplifying compliance with European Union average fleet CO₂ targets.

Furthermore, owners of PHEVs would pay about €500 more per year in operating expenses than would be assumed under lab tests.

“The strong claims that manufacturers like to make about their plug-in hybrid vehicles are clearly far from the truth,” commented a transport analyst. “Consumers are being misled into believing that by buying a PHEV, they are helping the planet and saving money. In reality, PHEVs are only slightly better than standard gas and diesel cars in terms of fuel consumption, CO₂ production, and operating expenses.”

Political Debate and Automotive Pressure

Plug-in hybrid cars have recently been brought back into policy discussions as automakers have pressed the European Union to weaken CO₂ targets. A planned ban on new combustion engine vehicles in 2035 has faced heavy lobbying from the car industry and resistance from EU countries with significant automotive industries.

Several high-level politicians have proposed PHEVs as a potential “compromise” option to include in the regulation.

An external energy policy expert, who was unaffiliated with the research, described the report a “very useful contribution” after a long period in which segments of the automotive sector claimed there was too little data to accurately assess real-world emissions.

“The results show, beyond any doubt, that the gap in official and real-world PHEV energy use and CO₂ emissions is significantly larger than for petrol or diesel vehicles,” the expert said. “All regulatory adjustments concerning PHEVs should be implemented with extreme care and in the light of this evidence.”