Plug-in Hybrid electric Cars Emit Almost as Much as Petrol Vehicles, Report Finds

Plug-in hybrid electric vehicles produce almost five times greater global warming emissions than lab-reported data show, as per a recent report.

Growing Discrepancy In Official and Real-World Emissions

Statistics shows that PHEVs release just 19% lower CO₂ than traditional gas and diesel vehicles, according to research carried out by a non-profit group. That differs significantly with lab estimates, which suggested a 75% reduction in pollution.

Analysts studied data from onboard energy use meters of 800,000 cars sold in Europe between 2021 and 2023. They discovered that real-world CO₂ emissions from PHEVs in 2023 were nearly five times higher than official estimates, up from 3.5 times in 2021.

“Real-world emissions are rising, while lab-reported figures are decreasing,” said a lead analyst involved in the study. “That discrepancy is widening and creates a significant issue. Consequently, PHEVs emit nearly as much as petrol cars.”

Primary Reasons Driving the Emissions Gap

Researchers linked the majority of the gap to overestimates of the “utility factor” – the ratio of kilometers travelled in electric power compared to total mileage. The team determined that just a quarter of driving was done in electric mode, while official assumptions assumed 84%.

Even, when running in electric mode, emission levels were significantly higher than lab estimates. This happened because electric motors were insufficiently powerful enough to function alone, leading to combustion motors burning gasoline for nearly a third of the travel covered in electric mode.

Regulatory and Economic Consequences

Based on estimates, the lowballing of PHEV CO2 output allowed four major carmaker companies to escape over €5bn in fines from 2021 and 2023, by artificially easing compliance with EU average fleet CO₂ targets.

Additionally, drivers of PHEVs would spend about €500 more per year in operating expenses than is assumed under laboratory conditions.

“The strong statements that manufacturers often promote about their PHEV cars are clearly far from the truth,” stated a transport expert. “Buyers are being misled into believing that by purchasing a PHEV, they are helping the environment and cutting costs. In reality, PHEVs are only slightly better than regular gas and diesel cars in terms of fuel consumption, CO₂ emissions, and running costs.”

Policy Discussion and Industry Pressure

Plug-in hybrid cars have lately been brought again into policy discussions as automakers have pressed the EU to relax CO₂ standards. A planned prohibition on sales of new combustion engine vehicles in 2035 has faced intense pressure from the car industry and resistance from EU countries with significant automotive industries.

Several high-level politicians have proposed PHEVs as a potential “flexibility” option to introduce in the legislation.

An independent energy policy specialist, who was unaffiliated with the research, described the report a “highly valuable addition” after years in which parts of the car industry argued there was insufficient information to accurately evaluate real-world emissions.

“The results show, without question, that the gap between lab and real-world PHEV energy use and CO₂ emissions is much, much larger than for petrol or diesel vehicles,” the expert said. “All regulatory adjustments concerning PHEVs should be made with utmost caution and considering that data.”