Plug in Hybrid Vehicles Emit Nearly as Much as Gasoline Vehicles, Study Finds

Plug-in hybrid electric vehicles produce nearly five times more global warming emissions than lab-reported figures show, as per a new report.

Widening Gap Between Official and Real-World CO2 Output

Data reveals that PHEVs release just 19% less CO₂ than conventional petrol and diesel cars, according to research carried out by a advocacy group. That contrasts significantly with laboratory estimates, which suggested a three-quarters reduction in pollution.

Analysts studied information from onboard energy use meters of eight hundred thousand vehicles registered in Europe between 2021 and 2023. The team found that actual CO₂ emissions from PHEVs in 2023 were 4.9 times greater than official estimates, up from 3.5 times in 2021.

“Actual emissions are increasing, while lab-reported figures are decreasing,” stated a lead researcher participating in the report. “That gap is growing and creates a serious issue. Consequently, PHEVs emit nearly as heavily as gasoline vehicles.”

Primary Factors Behind the Discrepancy

Researchers linked the majority of the gap to overestimates of the “utility factor” – the percentage of kilometers travelled in electric mode compared to overall distance. They determined that just 27% of driving was completed in EV mode, whereas official estimates assumed 84%.

Even, when running in electric mode, emission amounts were significantly higher than lab estimates. This occurred because electric motors were insufficiently powerful sufficient to function independently, resulting to combustion motors burning gasoline for nearly one-third of the travel covered in EV mode.

Regulatory and Economic Consequences

According to calculations, the underestimation of PHEV CO2 output allowed four large carmaker companies to escape more than €5bn in fines between 2021 and 2023, by falsely easing adherence with EU average fleet CO₂ standards.

Additionally, owners of PHEVs could spend approximately €500 extra annually in operating costs than would be assumed under lab conditions.

“The bold claims that manufacturers like to make about their PHEV cars are clearly way off the truth,” commented a transport analyst. “Buyers are being misled into thinking that by buying a PHEV, they are helping the environment and saving costs. In reality, PHEVs are little better than standard gas and diesel vehicles in terms of energy consumption, CO₂ production, and running expenses.”

Political Debate and Industry Pressure

Hybrid cars have lately been drawn again into political discussions as automakers have lobbied the EU to relax CO₂ targets. A planned prohibition on new combustion engine vehicles in 2035 has faced intense pressure from the automotive sector and opposition from member states with significant automotive manufacturing.

Some senior officials have proposed PHEVs as a potential “flexibility” option to introduce in the legislation.

One independent energy policy expert, who was unaffiliated with the research, called the analysis a “highly valuable addition” after a long period in which segments of the automotive sector argued there was too little information to accurately assess real-world emissions.

“These findings demonstrate, without question, that the difference in official and actual PHEV energy use and CO₂ emissions is significantly larger than for gasoline or diesel vehicles,” the expert said. “All policy changes concerning PHEVs should be implemented with utmost care and in the light of this data.”