🔗 Share this article

Plug-in hybrid cars produce nearly 5x greater global warming emissions than lab-reported data show, as per a recent analysis.

Widening Discrepancy In Lab and Real-World CO2 Output

Statistics shows that PHEVs release only one-fifth less CO₂ than conventional gas and diesel cars, based on research conducted by a advocacy organization. That contrasts significantly with lab estimates, which assumed a three-quarters reduction in pollution.

Analysts studied data from onboard energy use monitors of eight hundred thousand vehicles sold in the EU between 2021 and 2023. They found that actual CO₂ emissions from PHEVs in 2023 were 4.9 times greater than official estimates, increased from 3.5 times in 2021.

“Actual CO2 output are increasing, while lab-reported emissions are decreasing,” said a lead researcher participating in the study. “This discrepancy is growing and poses a serious issue. As a result, PHEVs emit almost as heavily as petrol cars.”

Key Factors Behind the Emissions Gap

Analysts linked most of the difference to overestimates of the “utility factor” – the ratio of miles travelled in electric mode compared to overall distance. They found that only a quarter of driving was done in EV mode, whereas lab estimates assumed 84%.

Even, when running in electric mode, emission amounts were well above official projections. This happened because electric motors were insufficiently powerful enough to function alone, resulting to engines using gasoline for nearly a third of the travel completed in EV mode.

Policy and Economic Consequences

According to calculations, the underestimation of PHEV emissions allowed four large automaker groups to avoid more than €5bn in penalties between 2021 and 2023, by falsely easing adherence with European Union average fleet CO₂ standards.

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

“The bold statements that manufacturers often promote about their PHEV cars are obviously far from the mark,” commented a automotive analyst. “Consumers are being duped into believing that by buying a PHEV, they are benefiting the planet and saving money. In reality, PHEVs are little better than standard petrol and diesel vehicles in terms of fuel use, CO₂ production, and operating expenses.”

Policy Discussion and Industry Lobbying

Hybrid cars have lately been brought back into political discussions as carmakers have lobbied the European Union to relax CO₂ standards. A proposed prohibition on new internal combustion vehicles in 2035 has faced heavy lobbying from the car industry and resistance from member states with significant car manufacturing.

Several high-level politicians have suggested plug-in hybrids as a possible “flexibility” solution to include in the legislation.

One independent energy economics specialist, who was unaffiliated with the research, described the analysis a “very useful contribution” after years in which segments of the automotive industry claimed there was too little information to accurately assess real-world CO2 output.

“These findings show, beyond any doubt, that the difference in lab and real-world PHEV energy use and CO₂ emissions is significantly larger than for petrol or conventional cars,” they said. “All regulatory adjustments regarding PHEVs should be made with extreme care and considering that data.”