🔗 Share this article

Plug-in hybrid cars produce nearly 5x greater planet-heating pollution than official figures indicate, as per a recent analysis.

Growing Discrepancy Between Official and Actual CO2 Output

Statistics shows that PHEVs emit just one-fifth lower CO₂ than traditional gas and diesel vehicles, according to research carried out by a non-profit organization. That differs sharply with lab estimates, which suggested a three-quarters decrease in pollution.

Analysts studied information from in-vehicle energy use monitors of 800,000 cars sold in Europe from 2021 and 2023. They discovered that real-world CO₂ output from PHEVs in 2023 were 4.9 times higher than lab estimates, up from three and a half times in 2021.

“Real-world CO2 output are increasing, while official emissions are falling,” stated a senior analyst participating in the report. “That discrepancy is widening and poses a serious issue. Consequently, PHEVs pollute nearly as much as gasoline vehicles.”

Key Factors Behind the Emissions Gap

Researchers attributed most of the gap to overestimates of the “electric driving share” – the percentage of miles driven in electric mode compared to total mileage. They found that just a quarter of driving was done in EV mode, while official estimates suggested 84%.

Even, when operating in electric mode, pollution levels were well above lab estimates. That occurred because EV motors were insufficiently powerful enough to function alone, leading to combustion motors burning gasoline for nearly a third of the travel completed in electric mode.

Policy and Financial Consequences

According to estimates, the lowballing of PHEV CO2 output enabled several large carmaker companies to escape more than €5bn in fines between 2021 and 2023, by artificially easing adherence with European Union average fleet CO₂ standards.

Furthermore, owners of PHEVs could spend about €500 more annually in operating costs than is assumed under lab tests.

“The strong statements that manufacturers often promote about their PHEV vehicles are clearly far from the truth,” stated a automotive analyst. “Buyers are being misled into believing that by buying a PHEV, they are helping the planet and cutting money. In reality, PHEVs are little improved than regular gas and diesel cars in terms of fuel consumption, CO₂ production, and operating costs.”

Policy Discussion and Automotive Pressure

Hybrid vehicles have recently been brought again into policy discussions as automakers have pressed the European Union to relax CO₂ standards. A proposed prohibition on sales of new internal combustion cars in 2035 has faced heavy lobbying from the car sector and opposition from EU countries with large automotive industries.

Several senior officials have proposed plug-in hybrids as a possible “flexibility” solution to include in the regulation.

An external energy policy specialist, who was unaffiliated with the research, described the report a “highly valuable contribution” after a long period in which parts of the automotive industry argued there was too little information to properly evaluate actual emissions.

“The results show, without question, that the gap between lab and real-world PHEV fuel consumption and CO₂ emissions is much, much greater than for gasoline or diesel cars,” they said. “Any policy adjustments concerning PHEVs should be implemented with utmost care and considering this evidence.”