🔗 Share this article

PHEVs emit nearly five times greater planet-heating emissions than official data indicate, as per a new analysis.

Growing Discrepancy In Lab and Actual CO2 Output

Statistics shows that PHEVs release just 19% less CO₂ than traditional gas and diesel cars, according to analysis conducted by a advocacy group. That differs significantly with laboratory estimates, which suggested a three-quarters decrease in emissions.

Analysts studied information from in-vehicle fuel consumption monitors of 800,000 vehicles registered in Europe from 2021 and 2023. The team found that actual CO₂ output from PHEVs in 2023 were 4.9 times greater than lab estimates, increased from three and a half times in 2021.

“Actual CO2 output are rising, while lab-reported emissions are falling,” stated a senior analyst participating in the report. “That gap is widening and creates a significant issue. As a result, PHEVs emit nearly as heavily as gasoline vehicles.”

Primary Factors Driving the Discrepancy

Analysts linked the majority of the gap to inflated estimates of the “electric driving share” – the ratio of kilometers travelled in electric mode compared to total distance. They found that just a quarter of travel was completed in EV mode, while lab estimates assumed over four-fifths.

Even, when running in EV mode, emission levels were well above lab estimates. That happened because EV motors were insufficiently powerful sufficient to operate independently, leading to combustion motors using fossil fuels for almost one-third of the distance completed in electric mode.

Regulatory and Financial Consequences

According to estimates, the underestimation of PHEV CO2 output allowed several major automaker groups to avoid over €5bn in penalties between 2021 and 2023, by falsely simplifying adherence with EU fleet-average CO₂ standards.

Additionally, owners of PHEVs would pay approximately €500 extra annually in running costs than would be assumed under lab tests.

“The bold statements that automakers often promote about their PHEV cars are clearly far from the mark,” commented a transport analyst. “Buyers are being duped into thinking that by purchasing a PHEV, they are helping the planet and saving money. Actually, PHEVs are little improved than regular gas and diesel cars in terms of fuel consumption, CO₂ production, and running costs.”

Political Discussion and Automotive Pressure

Plug-in hybrid cars have lately been brought back into policy debates as carmakers have lobbied the European Union to weaken CO₂ standards. A planned prohibition on sales of new internal combustion vehicles in 2035 has faced heavy lobbying from the car sector and opposition from EU countries with significant automotive industries.

Some senior politicians have suggested PHEVs as a potential “compromise” option to introduce in the regulation.

An external energy economics expert, who was not involved with the study, described the report a “highly valuable addition” after a long period in which parts of the car sector argued there was too little information to properly assess actual emissions.

“These findings demonstrate, without question, that the difference in lab and actual PHEV fuel consumption and CO₂ output is significantly greater than for gasoline or conventional vehicles,” the expert stated. “All policy adjustments concerning PHEVs should be implemented with extreme caution and in the light of this data.”