Plug-in Hybrid Cars Pollute Almost as Heavily as Petrol Cars, Study Finds

Plug-in hybrid electric vehicles release nearly 5x greater planet-heating emissions than official data show, as per a recent report.

Widening Discrepancy Between Lab and Actual CO2 Output

Statistics shows that PHEVs emit just 19% lower CO₂ than traditional gas and diesel cars, according to research conducted by a advocacy organization. That differs sharply with lab estimates, which assumed a three-quarters decrease in pollution.

Analysts studied data from in-vehicle fuel consumption meters of 800,000 vehicles sold in the EU from 2021 and 2023. They found that real-world CO₂ output from PHEVs in 2023 were nearly five times greater than lab estimates, up from 3.5 times in 2021.

“Real-world CO2 output are rising, while lab-reported emissions are decreasing,” stated a senior researcher involved in the report. “That gap is widening and creates a serious problem. Consequently, PHEVs pollute nearly as heavily as gasoline cars.”

Primary Reasons Behind the Emissions Gap

Analysts linked the majority of the gap to inflated estimates of the “utility factor” – the percentage of miles travelled in battery mode relative to total mileage. The team determined that only a quarter of travel was done in EV mode, while official estimates suggested 84%.

Even, when operating in electric mode, pollution amounts were significantly higher than lab estimates. That happened because electric motors were not strong enough to function alone, resulting to engines burning fossil fuels for almost a third of the travel completed in electric mode.

Policy and Economic Implications

Based on calculations, the underestimation of PHEV CO2 output allowed four major automaker groups to escape more than €5bn in penalties between 2021 and 2023, by artificially simplifying compliance with EU average fleet CO₂ standards.

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

“The strong claims that automakers often promote about their plug-in hybrid cars are clearly far from the truth,” commented a automotive analyst. “Buyers are being duped into believing that by purchasing a PHEV, they are helping the environment and cutting costs. Actually, PHEVs are only slightly improved than standard gas and diesel vehicles in terms of energy consumption, CO₂ production, and operating expenses.”

Political Debate and Automotive Lobbying

Hybrid vehicles have recently been drawn again into political discussions as automakers have pressed the European Union to weaken CO₂ standards. A planned ban on new internal combustion cars in 2035 has faced intense pressure from the car sector and resistance from EU countries with significant car industries.

Several senior politicians have suggested PHEVs as a possible “compromise” solution to include in the regulation.

One external energy economics expert, who was not involved with the study, called the report a “highly valuable addition” after years in which parts of the automotive sector argued there was too little information to accurately evaluate real-world emissions.

“These findings demonstrate, without question, that the difference in official and real-world PHEV fuel consumption and CO₂ emissions is significantly greater than for gasoline or conventional vehicles,” the expert stated. “All policy adjustments concerning PHEVs should be implemented with extreme care and considering this evidence.”