🔗 Share this article

PHEVs produce almost 5x greater planet-heating pollution than lab-reported figures indicate, according to a recent analysis.

Widening Discrepancy Between Official and Real-World Emissions

Statistics shows that PHEVs release only one-fifth less CO₂ than conventional gas and diesel vehicles, according to research conducted by a non-profit organization. That contrasts significantly with laboratory tests, which assumed a three-quarters reduction in emissions.

Analysts examined information from in-vehicle energy use meters of 800,000 cars sold in the EU from 2021 and 2023. They discovered that actual CO₂ output from PHEVs in 2023 were 4.9 times higher than official estimates, up from 3.5 times in 2021.

“Actual CO2 output are increasing, while lab-reported figures are decreasing,” said a senior analyst participating in the report. “This gap is widening and creates a serious problem. Consequently, PHEVs emit nearly as heavily as gasoline cars.”

Primary Reasons Behind the Emissions Gap

Researchers linked the majority of the difference to overestimates of the “electric driving share” – the percentage of miles driven in electric mode compared to overall distance. The team found that only a quarter of driving was completed in EV mode, whereas official assumptions assumed over four-fifths.

Even, when operating in EV mode, emission levels were well above official estimates. This happened because electric motors were not strong sufficient to function alone, resulting to combustion motors burning fossil fuels for almost one-third of the travel completed in EV mode.

Regulatory and Financial Consequences

According to calculations, the underestimation of PHEV CO2 output enabled four large automaker groups to escape over €5bn in penalties between 2021 and 2023, by artificially simplifying adherence with EU fleet-average CO₂ targets.

Additionally, owners of PHEVs could spend approximately €500 more annually in operating expenses than would be assumed under lab tests.

“The strong claims that manufacturers like to make about their PHEV vehicles are obviously way off the truth,” stated a automotive expert. “Buyers are being duped into believing that by buying a PHEV, they are helping the planet and saving money. Actually, PHEVs are little better than regular petrol and diesel cars in terms of fuel consumption, CO₂ production, and operating expenses.”

Political Discussion and Automotive Lobbying

Hybrid vehicles have lately been drawn again into policy discussions as carmakers have pressed the EU to weaken CO₂ targets. A planned prohibition on new internal combustion vehicles in 2035 has faced intense pressure from the car industry and opposition from EU countries with large car manufacturing.

Some senior politicians have proposed PHEVs as a potential “flexibility” option to include in the regulation.

One independent energy economics expert, who was not involved with the study, called the analysis a “highly valuable addition” after years in which segments of the automotive industry claimed there was too little information to accurately assess actual emissions.

“These findings show, beyond any doubt, that the difference in lab and real-world PHEV energy use and CO₂ emissions is significantly larger than for petrol or diesel cars,” they said. “Any policy adjustments regarding PHEVs should be made with extreme care and in the light of that data.”