Plug-in Hybrid Cars Pollute Nearly as Much as Petrol Cars, Report Finds

Plug-in hybrid electric vehicles emit nearly five times greater global warming emissions than lab-reported data show, as per a recent analysis.

Widening Discrepancy In Official and Real-World Emissions

Data shows that PHEVs release only 19% lower CO₂ than conventional petrol and diesel vehicles, based on analysis carried out by a advocacy group. This differs sharply with lab estimates, which suggested a 75% reduction in emissions.

Researchers examined information from onboard energy use meters of 800,000 vehicles sold in the EU between 2021 and 2023. They found that actual CO₂ emissions from PHEVs in 2023 were nearly five times higher than lab figures, increased from three and a half times in 2021.

“Real-world CO2 output are rising, while official emissions are decreasing,” said a lead analyst involved in the study. “That gap is growing and creates a significant issue. Consequently, PHEVs pollute nearly as much as petrol cars.”

Primary Reasons Driving the Emissions Gap

Analysts linked most of the difference to overestimates of the “utility factor” – the percentage of miles travelled in battery power compared to total mileage. They found that only a quarter of travel was completed in electric mode, while lab assumptions suggested over four-fifths.

Additionally, when running in EV mode, emission levels were significantly higher than official estimates. This happened because electric motors were not strong enough to operate independently, resulting to engines using gasoline for nearly a third of the travel completed in EV mode.

Policy and Economic Implications

Based on calculations, the lowballing of PHEV emissions allowed several large carmaker groups to avoid more than €5bn in fines from 2021 and 2023, by falsely simplifying adherence with EU fleet-average CO₂ targets.

Furthermore, drivers of PHEVs would spend about €500 extra annually in operating expenses than is estimated under laboratory tests.

“The strong statements that manufacturers often promote about their plug-in hybrid vehicles are clearly far from the mark,” stated a automotive analyst. “Consumers are being misled into thinking that by buying a PHEV, they are benefiting the planet and cutting costs. Actually, PHEVs are only slightly better than standard petrol and diesel cars in terms of fuel consumption, CO₂ production, and running expenses.”

Policy Discussion and Automotive Pressure

Plug-in hybrid cars have lately been brought back into political debates as automakers have lobbied the European Union to relax CO₂ standards. A planned ban on new internal combustion cars in 2035 has faced intense pressure from the automotive sector and opposition from member states with significant automotive manufacturing.

Several high-level officials have proposed plug-in hybrids as a potential “flexibility” option to include in the legislation.

An independent energy policy expert, who was unaffiliated with the research, called the analysis a “highly valuable addition” after years in which segments of the automotive industry argued there was too little information to properly assess real-world CO2 output.

“These findings demonstrate, beyond any doubt, that the difference between official and real-world PHEV fuel consumption and CO₂ output is much, much greater than for gasoline or diesel cars,” they said. “All policy changes concerning PHEVs should be implemented with extreme caution and considering this data.”