Plug in Hybrid electric Vehicles Pollute Nearly as Much as Gasoline Vehicles, Report Finds

PHEVs produce nearly 5x greater global warming emissions than lab-reported figures indicate, according to a recent report.

Growing Discrepancy Between Lab and Real-World CO2 Output

Data shows that PHEVs emit just 19% lower CO₂ than traditional petrol and diesel vehicles, according to analysis carried out by a non-profit organization. That differs significantly with laboratory tests, which suggested a three-quarters decrease in emissions.

Analysts examined data from in-vehicle fuel consumption monitors of 800,000 cars sold in Europe between 2021 and 2023. The team found that real-world CO₂ output from PHEVs in 2023 were nearly five times greater than official figures, up from 3.5 times in 2021.

“Real-world CO2 output are increasing, while official figures are decreasing,” stated a lead researcher participating in the study. “This discrepancy is widening and creates a serious issue. Consequently, PHEVs emit almost as heavily as petrol vehicles.”

Primary Factors Driving the Emissions Gap

Researchers linked most of the difference to inflated estimates of the “utility factor” – the percentage of miles travelled in battery mode relative to overall mileage. They determined that only 27% of driving was completed in electric mode, whereas official estimates suggested 84%.

Additionally, when running in EV mode, pollution levels were significantly higher than lab projections. This happened because EV motors were insufficiently powerful enough to function independently, resulting to engines using fossil fuels for nearly one-third of the distance covered in EV mode.

Regulatory and Economic Consequences

According to estimates, the lowballing of PHEV CO2 output enabled several major carmaker companies to escape more than €5bn in penalties from 2021 and 2023, by artificially simplifying adherence with EU fleet-average CO₂ standards.

Furthermore, owners of PHEVs could spend about €500 more per year in operating costs than is estimated under lab conditions.

“The bold statements that manufacturers like to make about their plug-in hybrid cars are clearly way off the truth,” stated a transport analyst. “Consumers are being duped into believing that by purchasing a PHEV, they are benefiting the planet and saving money. Actually, PHEVs are only slightly better than standard gas and diesel vehicles in terms of energy use, CO₂ production, and operating expenses.”

Political Discussion and Industry Lobbying

Hybrid vehicles have lately been drawn back into policy discussions as carmakers have lobbied the European Union to relax CO₂ targets. A proposed prohibition on new combustion engine vehicles in 2035 has faced heavy lobbying from the car sector and opposition from member states with significant car manufacturing.

Some high-level politicians have proposed PHEVs as a possible “flexibility” solution to introduce in the regulation.

An independent energy economics specialist, who was not involved with the research, called the analysis a “very useful contribution” after a long period in which segments of the car industry claimed there was insufficient data to properly assess real-world CO2 output.

“These findings show, without question, that the difference in official and real-world PHEV fuel consumption and CO₂ emissions is much, much larger than for gasoline or conventional vehicles,” they stated. “Any policy adjustments regarding PHEVs should be made with utmost caution and considering that data.”