Plug in Hybrid electric Vehicles Emit Almost as Much as Petrol Vehicles, Study Reveals

PHEVs release nearly 5x more global warming emissions than official data show, according to a new analysis.

Widening Discrepancy In Official and Actual Emissions

Statistics shows that PHEVs emit only one-fifth less CO₂ than traditional gas and diesel vehicles, based on research conducted by a advocacy group. This differs sharply with laboratory estimates, which assumed a three-quarters reduction in pollution.

Analysts studied data from onboard fuel consumption monitors of eight hundred thousand vehicles registered in the EU from 2021 and 2023. The team discovered that actual CO₂ emissions from PHEVs in 2023 were 4.9 times greater than official figures, up from three and a half times in 2021.

“Real-world CO2 output are increasing, while official emissions are falling,” said a senior analyst participating in the report. “This gap is growing and poses a serious problem. Consequently, PHEVs emit nearly as much as petrol vehicles.”

Primary Reasons Behind the Emissions Gap

Researchers linked the majority of the difference to inflated estimates of the “utility factor” – the ratio of kilometers driven in electric mode relative to total mileage. They found that just a quarter of driving was done in electric mode, while official assumptions suggested over four-fifths.

Even, when running in EV mode, emission levels were significantly higher than lab projections. This happened because electric motors were insufficiently powerful enough to function alone, resulting to combustion motors using fossil fuels for almost one-third of the distance covered in EV mode.

Regulatory and Financial Consequences

Based on calculations, the lowballing of PHEV CO2 output allowed four large carmaker groups to avoid over €5bn in penalties between 2021 and 2023, by falsely simplifying compliance with European Union fleet-average CO₂ targets.

Furthermore, drivers of PHEVs would spend about €500 more annually in running costs than is estimated under laboratory conditions.

“The strong claims that manufacturers like to make about their PHEV cars are obviously far from the mark,” stated a transport analyst. “Buyers are being misled into believing that by purchasing a PHEV, they are benefiting the environment and cutting money. Actually, PHEVs are only slightly better than regular gas and diesel cars in terms of energy consumption, CO₂ emissions, and operating costs.”

Policy Debate and Automotive Pressure

Hybrid cars have lately been drawn again into political debates as carmakers have lobbied the EU to relax CO₂ standards. A planned ban on new combustion engine vehicles in 2035 has faced intense pressure from the car sector and opposition from EU countries with significant car manufacturing.

Some senior politicians have proposed plug-in hybrids as a potential “flexibility” solution to include in the legislation.

One external energy economics expert, who was not involved with the study, called the report a “highly valuable addition” after a long period in which segments of the automotive sector claimed there was insufficient information to properly evaluate actual emissions.

“These findings demonstrate, without question, that the difference in official and real-world PHEV energy use and CO₂ emissions is much, much greater than for petrol or conventional cars,” they stated. “All policy adjustments concerning PHEVs should be implemented with extreme caution and considering that data.”