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

PHEVs produce almost 5x more global warming pollution than official data show, according to a new report.

Widening Discrepancy Between Lab and Real-World CO2 Output

Statistics shows that PHEVs emit just one-fifth lower CO₂ than traditional petrol and diesel cars, according to research conducted by a advocacy group. This differs significantly with lab estimates, which assumed a three-quarters reduction in emissions.

Analysts examined data from onboard fuel consumption monitors of eight hundred thousand cars registered in Europe from 2021 and 2023. They discovered that real-world CO₂ emissions from PHEVs in 2023 were 4.9 times higher than official estimates, up from 3.5 times in 2021.

“Actual emissions are increasing, while lab-reported figures are falling,” stated a lead researcher participating in the study. “This gap is growing and poses a serious issue. As a result, PHEVs emit almost as much as petrol vehicles.”

Primary Reasons Driving the Discrepancy

Analysts linked the majority of the gap to overestimates of the “electric driving share” – the percentage of miles travelled in battery power relative to total mileage. The team found that just 27% of travel was done in EV mode, while lab estimates assumed 84%.

Additionally, when running in electric mode, emission levels were significantly higher than official projections. This occurred because EV motors were insufficiently powerful sufficient to operate independently, resulting to combustion motors using gasoline for almost a third of the distance completed in electric mode.

Policy and Financial Implications

According to calculations, the lowballing 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, owners of PHEVs could spend approximately €500 extra annually in operating expenses than would be assumed under laboratory tests.

“The strong statements that manufacturers often promote about their plug-in hybrid cars are clearly way off the mark,” commented a automotive expert. “Consumers are being duped into believing that by buying a PHEV, they are helping the planet and cutting costs. In reality, PHEVs are little improved than standard gas and diesel cars in terms of energy consumption, CO₂ production, and operating expenses.”

Political Discussion and Industry Pressure

Hybrid cars have lately been brought again into political debates as carmakers have pressed the EU to weaken CO₂ standards. A planned ban on sales of new combustion engine cars in 2035 has faced intense pressure from the automotive industry and opposition from EU countries with large automotive manufacturing.

Several senior officials have proposed PHEVs as a possible “flexibility” option to include in the regulation.

An independent energy policy expert, who was not involved with the study, called the analysis a “very useful contribution” after years in which segments of the automotive sector claimed there was insufficient information to properly assess actual emissions.

“The results demonstrate, without question, that the gap in official and real-world PHEV fuel consumption and CO₂ output is much, much greater than for petrol or conventional cars,” the expert stated. “All policy adjustments regarding PHEVs should be made with extreme caution and considering that data.”