🔗 Share this article

Plug-in hybrid electric vehicles emit almost five times greater planet-heating emissions than official figures show, as per a recent analysis.

Widening Discrepancy In Official and Real-World CO2 Output

Data reveals that PHEVs release only one-fifth less CO₂ than conventional petrol and diesel vehicles, based on research carried out by a advocacy organization. This contrasts sharply with lab tests, which assumed a three-quarters decrease in pollution.

Researchers studied information from in-vehicle energy use meters of 800,000 cars registered in Europe from 2021 and 2023. They discovered that real-world CO₂ emissions from PHEVs in 2023 were nearly five times higher than official estimates, up from 3.5 times in 2021.

“Actual emissions are increasing, while official figures are decreasing,” said a senior analyst participating in the study. “This discrepancy is widening and creates a serious problem. Consequently, PHEVs pollute almost as much as petrol vehicles.”

Key Factors Behind the Emissions Gap

Analysts linked most of the difference to overestimates of the “utility factor” – the percentage of miles travelled in electric mode compared to total distance. The team determined that only a quarter of driving was done in EV mode, while official assumptions suggested over four-fifths.

Even, when operating in EV mode, pollution levels were well above official projections. This happened because electric motors were not strong enough to operate independently, resulting to engines using fossil fuels for almost a third of the travel completed in EV mode.

Regulatory and Economic Consequences

According to calculations, the underestimation of PHEV emissions enabled several major carmaker companies to escape more than €5bn in fines from 2021 and 2023, by falsely easing compliance with European Union fleet-average CO₂ targets.

Furthermore, drivers of PHEVs could pay approximately €500 more annually in operating expenses than is estimated under laboratory conditions.

“The bold statements that automakers like to make about their PHEV vehicles are clearly way off the truth,” stated a automotive analyst. “Buyers are being misled into thinking that by buying a PHEV, they are helping the planet and saving costs. Actually, PHEVs are only slightly better than regular gas and diesel cars in terms of energy consumption, CO₂ production, and operating expenses.”

Policy Discussion and Automotive Pressure

Plug-in hybrid vehicles have recently been drawn again into policy discussions as carmakers have lobbied the European Union to relax CO₂ standards. A planned prohibition on sales of new internal combustion vehicles in 2035 has faced heavy lobbying from the automotive sector and opposition from EU countries with significant automotive industries.

Some senior officials have proposed PHEVs as a possible “flexibility” solution to include in the legislation.

One independent energy policy expert, who was not involved with the study, described the analysis a “highly valuable contribution” after a long period in which segments of the car industry argued there was too little information to properly assess actual CO2 output.

“These findings show, beyond any doubt, that the gap between official and actual PHEV energy use and CO₂ emissions is significantly larger than for petrol or diesel vehicles,” the expert said. “Any regulatory changes regarding PHEVs should be implemented with utmost care and considering this data.”