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

Plug-in hybrid cars release almost 5x more global warming pollution than official figures show, as per a new analysis.

Growing Discrepancy Between Official and Real-World Emissions

Statistics reveals that PHEVs emit just one-fifth lower CO₂ than traditional petrol and diesel vehicles, according to research conducted by a advocacy organization. That contrasts significantly with laboratory tests, which suggested a three-quarters decrease in pollution.

Analysts examined data from in-vehicle energy use monitors of eight hundred thousand cars sold in Europe from 2021 and 2023. The team found that actual CO₂ emissions from PHEVs in 2023 were nearly five times greater than official estimates, increased from 3.5 times in 2021.

“Actual emissions are increasing, while lab-reported emissions are falling,” stated a senior researcher participating in the report. “That gap is growing and poses a significant issue. Consequently, PHEVs pollute nearly as heavily as petrol vehicles.”

Key Factors Driving the Discrepancy

Analysts linked the majority of the difference to inflated estimates of the “utility factor” – the ratio of kilometers travelled in battery mode compared to overall mileage. They determined that only 27% of travel was completed in EV mode, while official estimates assumed 84%.

Even, when running in electric mode, pollution amounts were significantly higher than lab estimates. This happened because EV motors were insufficiently powerful sufficient to operate independently, resulting to combustion motors burning gasoline for almost one-third of the distance completed in EV mode.

Policy and Financial Consequences

Based on estimates, the lowballing of PHEV emissions allowed several major automaker companies to avoid over €5bn in fines between 2021 and 2023, by falsely easing adherence with European Union fleet-average CO₂ standards.

Furthermore, owners of PHEVs would spend approximately €500 extra per year in running costs than is assumed under laboratory tests.

“The bold claims that automakers often promote about their plug-in hybrid vehicles are clearly way off the truth,” stated a automotive expert. “Consumers are being misled into believing that by purchasing a PHEV, they are benefiting the environment and saving money. In reality, PHEVs are only slightly improved than regular petrol and diesel cars in terms of fuel consumption, CO₂ emissions, and running expenses.”

Political Debate and Industry Pressure

Plug-in hybrid vehicles have lately been drawn again into political discussions as carmakers have pressed the EU to weaken CO₂ targets. A proposed ban on sales of new combustion engine cars in 2035 has faced heavy pressure from the automotive industry and resistance from EU countries with significant automotive industries.

Several high-level officials have suggested PHEVs as a potential “compromise” option to include in the legislation.

One independent energy economics specialist, who was unaffiliated with the study, called the analysis a “highly valuable contribution” after a long period in which segments of the automotive sector argued there was insufficient data to accurately evaluate real-world emissions.

“The results show, beyond any doubt, that the difference in lab and actual PHEV energy use and CO₂ emissions is much, much larger than for petrol or diesel cars,” the expert said. “All regulatory adjustments concerning PHEVs should be implemented with utmost care and considering this evidence.”