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

Plug-in hybrid electric vehicles emit almost five times more planet-heating pollution than lab-reported figures show, as per a new report.

Widening Gap Between Official and Real-World CO2 Output

Data shows that PHEVs emit just 19% less CO₂ than traditional petrol and diesel cars, according to research conducted by a advocacy organization. That differs significantly with lab tests, which assumed a three-quarters decrease in emissions.

Researchers examined data from onboard energy use monitors of eight hundred thousand cars sold in Europe between 2021 and 2023. They found that actual CO₂ emissions from PHEVs in 2023 were 4.9 times greater than lab estimates, increased from three and a half times in 2021.

“Actual CO2 output are increasing, while lab-reported emissions are decreasing,” stated a senior researcher involved in the report. “That discrepancy is widening and poses a serious issue. Consequently, PHEVs pollute almost as heavily as petrol cars.”

Primary Reasons Driving the Discrepancy

Analysts linked most of the difference to overestimates of the “electric driving share” – the percentage of miles travelled in battery power relative to overall distance. They determined that only 27% of travel was done in electric mode, while official assumptions suggested over four-fifths.

Additionally, when operating in electric mode, pollution levels were significantly higher than lab projections. This happened because electric motors were insufficiently powerful enough to operate independently, leading to engines using gasoline for nearly a third of the travel completed in EV mode.

Regulatory and Economic Implications

Based on calculations, the lowballing of PHEV emissions allowed several large automaker groups to avoid more than €5bn in penalties from 2021 and 2023, by artificially easing compliance with EU average fleet CO₂ standards.

Additionally, drivers of PHEVs could spend about €500 more annually in operating costs than would be assumed under laboratory tests.

“The bold claims that automakers often promote about their PHEV cars are clearly far from the truth,” stated a automotive expert. “Consumers are being misled into believing that by buying a PHEV, they are helping the environment and cutting costs. Actually, PHEVs are only slightly better than regular gas and diesel cars in terms of energy use, CO₂ emissions, and operating expenses.”

Policy Debate and Industry Lobbying

Hybrid cars have recently been drawn back into political discussions as carmakers have lobbied the EU to relax CO₂ standards. A proposed ban on sales of new combustion engine vehicles in 2035 has faced intense lobbying from the automotive industry and resistance from EU countries with significant car industries.

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

An external energy policy specialist, who was not involved with the study, called the analysis a “very useful contribution” after a long period in which segments of the automotive industry argued there was too little data to properly evaluate actual CO2 output.

“The results demonstrate, beyond any doubt, that the gap in lab and real-world PHEV fuel consumption and CO₂ output is much, much greater than for gasoline or conventional vehicles,” they said. “Any regulatory changes concerning PHEVs should be made with utmost caution and considering that evidence.”