🔗 Share this article

PHEVs emit almost five times more global warming emissions than official data show, as per a new analysis.

Growing Gap In Official and Actual CO2 Output

Data reveals that PHEVs emit only 19% less CO₂ than traditional petrol and diesel cars, according to research conducted by a advocacy organization. That differs sharply with laboratory tests, which assumed a 75% reduction in pollution.

Analysts examined data from onboard fuel consumption monitors of eight hundred thousand vehicles sold in the EU from 2021 and 2023. They found that real-world CO₂ output from PHEVs in 2023 were nearly five times greater than official estimates, increased from three and a half times in 2021.

“Actual CO2 output are rising, while lab-reported figures are falling,” stated a senior analyst participating in the report. “This discrepancy is growing and creates a serious problem. As a result, PHEVs pollute almost as much as petrol vehicles.”

Key Factors Driving the Emissions Gap

Analysts attributed most of the gap to overestimates of the “utility factor” – the ratio of miles travelled in electric power compared to total mileage. The team determined that just a quarter of driving was completed in electric mode, while lab estimates assumed 84%.

Additionally, when operating in EV mode, pollution amounts were significantly higher than lab estimates. That happened because electric motors were insufficiently powerful sufficient to function independently, resulting to combustion motors burning fossil fuels for almost one-third of the travel completed in electric mode.

Regulatory and Economic Implications

Based on estimates, the underestimation of PHEV emissions allowed several large carmaker groups to escape more than €5bn in fines from 2021 and 2023, by artificially simplifying compliance with EU fleet-average CO₂ standards.

Additionally, owners of PHEVs would pay about €500 more per year in operating expenses than would be assumed under laboratory tests.

“The bold claims that automakers like to make about their plug-in hybrid cars are clearly way off the mark,” commented a transport expert. “Consumers are being duped into thinking that by purchasing a PHEV, they are benefiting the planet and cutting costs. Actually, PHEVs are only slightly better than standard gas and diesel vehicles in terms of fuel consumption, CO₂ emissions, and running costs.”

Policy Debate and Automotive Pressure

Hybrid vehicles have lately been drawn back into political debates as automakers have lobbied the EU to relax CO₂ standards. A planned prohibition on new combustion engine vehicles in 2035 has faced heavy pressure from the automotive sector and resistance from EU countries with large car industries.

Several senior politicians have suggested plug-in hybrids as a possible “compromise” option to include in the regulation.

An external energy policy specialist, who was unaffiliated with the research, described the analysis a “highly valuable addition” after years in which parts of the car industry argued there was insufficient information to accurately evaluate actual CO2 output.

“The results demonstrate, beyond any doubt, that the difference between official and actual PHEV fuel consumption and CO₂ output is much, much larger than for gasoline or diesel cars,” the expert stated. “Any regulatory adjustments concerning PHEVs should be made with extreme care and in the light of that data.”