🔗 Share this article

Plug-in hybrid cars emit almost five times greater global warming emissions than official data show, as per a recent report.

Widening Discrepancy Between Lab and Actual CO2 Output

Data shows that PHEVs emit only 19% lower CO₂ than traditional gas and diesel cars, according to research conducted by a non-profit organization. This differs sharply with laboratory tests, which suggested a three-quarters reduction in pollution.

Analysts studied information from onboard energy use meters of 800,000 cars registered in the EU from 2021 and 2023. The team discovered that real-world CO₂ emissions from PHEVs in 2023 were nearly five times higher than official estimates, up from three and a half times in 2021.

“Real-world CO2 output are increasing, while lab-reported figures are falling,” stated a senior researcher involved in the report. “That discrepancy is widening and creates a significant issue. Consequently, PHEVs pollute nearly as heavily as gasoline vehicles.”

Key Reasons Behind the Discrepancy

Analysts attributed most of the gap to inflated estimates of the “utility factor” – the ratio of kilometers travelled in electric power compared to overall mileage. The team found that just 27% of driving was completed in electric mode, whereas official assumptions assumed over four-fifths.

Even, when operating in electric mode, emission levels were well above official projections. This happened because EV motors were insufficiently powerful sufficient to function independently, leading to combustion motors burning fossil fuels for almost one-third of the distance completed in electric mode.

Regulatory and Economic Consequences

Based on estimates, the lowballing of PHEV emissions allowed several large automaker groups to avoid more than €5bn in fines between 2021 and 2023, by falsely simplifying adherence with European Union fleet-average CO₂ standards.

Furthermore, drivers of PHEVs would pay about €500 more annually in operating expenses than would be estimated under laboratory conditions.

“The strong statements that manufacturers like to make about their plug-in hybrid vehicles are clearly way off the truth,” commented a transport expert. “Consumers are being duped into thinking that by buying a PHEV, they are helping the environment and saving costs. Actually, PHEVs are little improved than standard gas and diesel cars in terms of energy use, CO₂ emissions, and running expenses.”

Policy Debate and Industry Lobbying

Plug-in hybrid cars have recently been brought back into policy discussions as carmakers have lobbied the European Union to relax CO₂ targets. A planned prohibition on sales of new combustion engine cars in 2035 has faced intense lobbying from the automotive industry and resistance from member states with significant automotive industries.

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

One independent energy policy specialist, who was not involved with the study, called the analysis a “highly valuable contribution” after years in which parts of the car sector argued there was too little information to accurately assess real-world emissions.

“These findings demonstrate, without question, that the difference between lab and actual PHEV fuel consumption and CO₂ emissions is much, much larger than for petrol or conventional vehicles,” the expert said. “All regulatory adjustments concerning PHEVs should be made with utmost care and in the light of this data.”