Plug in Hybrid Vehicles Emit Nearly as Heavily as Petrol Cars, Study Finds

Plug-in hybrid electric vehicles produce nearly 5x more planet-heating pollution than official data show, as per a recent analysis.

Growing Discrepancy In Official and Actual CO2 Output

Data shows that PHEVs release only one-fifth lower CO₂ than conventional gas and diesel vehicles, according to research carried out by a advocacy group. This contrasts sharply with laboratory tests, which suggested a three-quarters decrease in emissions.

Researchers studied information from onboard energy use meters of eight hundred thousand vehicles registered in Europe between 2021 and 2023. They discovered that real-world CO₂ emissions from PHEVs in 2023 were nearly five times higher than lab figures, up from 3.5 times in 2021.

“Actual emissions are rising, while lab-reported figures are decreasing,” said a senior analyst participating in the study. “This discrepancy is widening and poses a serious issue. As a result, PHEVs emit almost as heavily as gasoline cars.”

Key Factors Driving the Emissions Gap

Analysts attributed the majority of the gap to overestimates of the “utility factor” – the percentage of miles travelled in battery power relative to total distance. They determined that only 27% of driving was completed in EV mode, while official assumptions suggested 84%.

Even, when running in EV mode, emission levels were well above lab estimates. This occurred because EV motors were insufficiently powerful enough to function alone, leading to engines burning gasoline for nearly a third of the distance completed in electric mode.

Policy and Economic Consequences

Based on estimates, the lowballing of PHEV emissions allowed several major carmaker companies to avoid over €5bn in penalties between 2021 and 2023, by falsely simplifying compliance with EU average fleet CO₂ targets.

Furthermore, drivers of PHEVs would spend approximately €500 more annually in running expenses than is assumed under lab tests.

“The strong claims that automakers often promote about their plug-in hybrid cars are obviously far from the mark,” commented a automotive analyst. “Buyers are being duped into believing that by purchasing a PHEV, they are benefiting the environment and saving money. Actually, PHEVs are only slightly better than regular gas and diesel vehicles in terms of fuel consumption, CO₂ emissions, and running expenses.”

Political Discussion and Automotive Lobbying

Plug-in hybrid vehicles have recently been drawn again into political discussions as carmakers have pressed the EU to relax CO₂ targets. A planned prohibition on sales of new combustion engine cars in 2035 has faced intense pressure from the car industry and opposition from EU countries with large car manufacturing.

Some senior politicians have proposed plug-in hybrids as a possible “compromise” solution to introduce in the legislation.

An external energy economics expert, who was not involved with the study, called the analysis a “highly valuable addition” after years in which segments of the car industry argued there was too little information to accurately evaluate real-world CO2 output.

“The results demonstrate, beyond any doubt, that the gap between lab and real-world PHEV energy use and CO₂ output is significantly greater than for petrol or diesel cars,” they said. “All policy changes concerning PHEVs should be implemented with utmost care and considering that evidence.”