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Plug-in hybrid cars release nearly 5x greater global warming pollution than lab-reported figures indicate, as per a recent report.

Widening Gap In Lab and Actual CO2 Output

Statistics shows that PHEVs release only 19% lower CO₂ than conventional petrol and diesel cars, according to analysis conducted by a advocacy organization. This contrasts sharply with lab estimates, which suggested a three-quarters decrease in emissions.

Analysts studied data from in-vehicle fuel consumption monitors of 800,000 vehicles sold in the EU from 2021 and 2023. They discovered that real-world CO₂ emissions from PHEVs in 2023 were 4.9 times greater than official estimates, increased from 3.5 times in 2021.

“Real-world CO2 output are increasing, while lab-reported emissions are falling,” said a senior analyst involved in the report. “That discrepancy is growing and poses a significant issue. As a result, PHEVs pollute almost as much as petrol vehicles.”

Key Factors Driving the Emissions Gap

Researchers linked the majority of the gap to inflated estimates of the “electric driving share” – the percentage of miles driven in battery power compared to total mileage. They found that just 27% of driving was done in electric mode, while lab estimates suggested 84%.

Even, when operating in EV mode, pollution amounts were significantly higher than lab estimates. That happened because electric motors were insufficiently powerful enough to operate independently, resulting to combustion motors burning fossil fuels for nearly one-third of the travel covered in EV mode.

Policy and Financial Consequences

According to calculations, the lowballing of PHEV CO2 output enabled several major carmaker groups to escape over €5bn in fines between 2021 and 2023, by falsely simplifying compliance with EU fleet-average CO₂ standards.

Additionally, drivers of PHEVs would spend about €500 extra per year in operating costs than would be assumed under lab conditions.

“The strong statements that manufacturers like to make about their PHEV cars are clearly far from the truth,” stated a transport expert. “Consumers are being duped into believing that by purchasing a PHEV, they are benefiting the environment and saving costs. In reality, PHEVs are only slightly better than standard gas and diesel cars in terms of energy consumption, CO₂ emissions, and running costs.”

Political Debate and Automotive Pressure

Hybrid vehicles have lately been brought back into political debates as automakers have pressed the EU to weaken CO₂ targets. A planned ban on sales of new combustion engine cars in 2035 has faced heavy pressure from the car industry and resistance from EU countries with large automotive industries.

Some high-level officials have suggested plug-in hybrids as a possible “compromise” solution to introduce in the regulation.

One independent energy policy specialist, who was unaffiliated with the research, described the analysis a “very useful contribution” after a long period in which parts of the car industry argued there was insufficient data to accurately evaluate real-world CO2 output.

“The results show, beyond any doubt, that the gap between official and actual PHEV fuel consumption and CO₂ emissions is significantly larger than for gasoline or diesel cars,” the expert stated. “Any policy changes regarding PHEVs should be made with utmost care and in the light of that evidence.”