Plug in Hybrid electric Cars Pollute Nearly as Much as Petrol Vehicles, Study Finds

Plug-in hybrid electric vehicles emit nearly 5x greater global warming emissions than lab-reported figures indicate, as per a new report.

Growing Discrepancy Between Lab and Actual CO2 Output

Data shows that PHEVs emit only 19% less CO₂ than conventional gas and diesel vehicles, according to research carried out by a non-profit organization. That differs significantly with lab tests, which suggested a 75% decrease in emissions.

Researchers studied information from onboard fuel consumption monitors of eight hundred thousand vehicles sold in the EU from 2021 and 2023. The team found that actual CO₂ output from PHEVs in 2023 were 4.9 times higher than official estimates, increased from three and a half times in 2021.

“Real-world CO2 output are increasing, while lab-reported emissions are decreasing,” stated a senior analyst participating in the study. “This gap is widening and poses a significant issue. As a result, PHEVs emit almost as much as petrol vehicles.”

Key Reasons Driving the Discrepancy

Analysts linked the majority of the difference to inflated estimates of the “utility factor” – the percentage of kilometers driven in electric power compared to total distance. The team determined that just 27% of driving was done in EV mode, whereas lab assumptions suggested 84%.

Even, when running in EV mode, emission amounts were significantly higher than lab estimates. This happened because electric motors were insufficiently powerful sufficient to operate alone, leading to engines using fossil fuels for nearly a third of the travel covered in electric mode.

Regulatory and Financial Consequences

According to estimates, the underestimation of PHEV emissions allowed four major carmaker companies to avoid more than €5bn in fines between 2021 and 2023, by artificially easing compliance with European Union average fleet CO₂ standards.

Additionally, drivers of PHEVs would pay about €500 extra per year in running costs than would be assumed under laboratory tests.

“The bold statements that automakers like to make about their PHEV vehicles are clearly way off the mark,” stated a automotive analyst. “Buyers are being duped into thinking that by buying a PHEV, they are helping the planet and cutting costs. Actually, PHEVs are only slightly improved than regular petrol and diesel cars in terms of energy consumption, CO₂ production, and operating expenses.”

Political Debate and Automotive Pressure

Hybrid cars have lately been drawn back into policy discussions as automakers have pressed the EU to weaken CO₂ targets. A planned prohibition on sales of new combustion engine vehicles in 2035 has faced intense lobbying from the car sector and resistance from EU countries with large car industries.

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

An external energy policy expert, who was unaffiliated with the study, described the analysis a “highly valuable contribution” after years in which segments of the automotive industry claimed there was insufficient information to properly assess actual CO2 output.

“The results show, beyond any doubt, that the gap between official and actual PHEV fuel consumption and CO₂ emissions is significantly larger than for petrol or diesel cars,” the expert stated. “All policy changes concerning PHEVs should be implemented with utmost care and considering this data.”