🔗 Share this article

Plug-in hybrid cars release nearly 5x more planet-heating emissions than lab-reported figures show, according to a recent report.

Widening Gap Between Lab and Actual Emissions

Statistics reveals that PHEVs release only one-fifth lower CO₂ than traditional gas and diesel vehicles, according to research conducted by a non-profit organization. This differs significantly with laboratory tests, which assumed a three-quarters decrease in pollution.

Researchers examined data from onboard energy use monitors of eight hundred thousand vehicles registered in Europe from 2021 and 2023. The team found that real-world CO₂ output from PHEVs in 2023 were 4.9 times higher than lab figures, increased from 3.5 times in 2021.

“Actual CO2 output are increasing, while lab-reported figures are falling,” stated a lead analyst participating in the report. “This gap is growing and poses a significant issue. As a result, PHEVs pollute nearly as much as petrol vehicles.”

Key Factors Behind the Discrepancy

Analysts attributed most of the gap to inflated estimates of the “utility factor” – the ratio of kilometers driven in electric power compared to overall distance. They found that just 27% of driving was done in electric mode, while lab assumptions suggested over four-fifths.

Additionally, when running in EV mode, pollution levels were well above lab projections. This occurred because electric motors were not strong sufficient to function alone, resulting to engines burning fossil fuels for almost a third of the distance completed in electric mode.

Regulatory and Financial Consequences

According to estimates, the lowballing of PHEV emissions allowed several large carmaker companies to avoid over €5bn in penalties from 2021 and 2023, by falsely easing compliance with EU average fleet CO₂ targets.

Additionally, drivers of PHEVs could pay about €500 extra annually in running costs than would be assumed under lab tests.

“The strong statements that automakers like to make about their PHEV cars are obviously way off the mark,” commented a automotive expert. “Consumers are being misled into believing that by buying a PHEV, they are helping the environment and cutting costs. In reality, PHEVs are only slightly improved than standard gas and diesel vehicles in terms of energy consumption, CO₂ emissions, and operating costs.”

Political Debate and Automotive Pressure

Hybrid cars have lately been drawn back into political debates as carmakers have pressed the European Union to relax CO₂ targets. A proposed ban on sales of new combustion engine cars in 2035 has faced intense pressure from the car industry and opposition from EU countries with large car industries.

Several senior politicians have proposed plug-in hybrids as a potential “compromise” option to introduce in the legislation.

An external energy economics specialist, who was unaffiliated with the research, called the report a “very useful addition” after years in which segments of the automotive sector argued there was too little information to accurately evaluate real-world emissions.

“These findings demonstrate, beyond any doubt, that the gap between lab and actual PHEV fuel consumption and CO₂ output is much, much greater than for petrol or conventional vehicles,” the expert stated. “Any policy changes concerning PHEVs should be implemented with extreme care and considering that data.”