Plug in Hybrid electric Vehicles Pollute Nearly as Much as Gasoline Vehicles, Report Reveals

Plug-in hybrid electric vehicles emit nearly 5x greater planet-heating pollution than lab-reported data show, according to a recent analysis.

Growing Gap Between Official and Real-World Emissions

Statistics shows that PHEVs emit just one-fifth less CO₂ than conventional gas and diesel vehicles, according to analysis conducted by a non-profit group. This contrasts sharply with laboratory estimates, which assumed a three-quarters reduction in pollution.

Analysts examined information from in-vehicle fuel consumption monitors of 800,000 vehicles registered in Europe between 2021 and 2023. They found that real-world CO₂ output from PHEVs in 2023 were nearly five times higher than official estimates, increased from 3.5 times in 2021.

“Real-world emissions are rising, while official emissions are decreasing,” stated a lead researcher participating in the study. “That gap is widening and creates a significant problem. Consequently, PHEVs emit nearly as heavily as petrol vehicles.”

Key Reasons Driving the Emissions Gap

Researchers attributed the majority of the gap to overestimates of the “utility factor” – the ratio of miles driven in electric mode compared to overall mileage. The team determined that only a quarter of driving was done in EV mode, while lab assumptions assumed over four-fifths.

Additionally, when running in EV mode, pollution amounts were well above official estimates. That happened because electric motors were insufficiently powerful enough to operate independently, resulting to combustion motors burning fossil fuels for nearly one-third of the travel completed in electric mode.

Policy and Economic Implications

According to estimates, the lowballing of PHEV CO2 output enabled four major automaker groups to escape over €5bn in fines between 2021 and 2023, by artificially simplifying adherence with European Union average fleet CO₂ targets.

Furthermore, owners of PHEVs could spend approximately €500 more per year in operating expenses than would be assumed under lab tests.

“The strong claims that manufacturers like to make about their plug-in hybrid vehicles are obviously way off the mark,” commented a transport expert. “Buyers are being misled into believing that by buying a PHEV, they are helping the planet and saving costs. In reality, PHEVs are only slightly improved than regular gas and diesel cars in terms of fuel consumption, CO₂ production, and operating expenses.”

Political Discussion and Automotive Lobbying

Hybrid vehicles have lately been brought back into policy debates as automakers have lobbied the EU to relax CO₂ standards. A proposed ban on new combustion engine cars in 2035 has faced intense pressure from the car sector and opposition from EU countries with large automotive industries.

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

One external energy policy specialist, who was unaffiliated with the study, described the analysis a “highly valuable contribution” after years in which segments of the automotive industry argued there was too little data to accurately evaluate real-world CO2 output.

“These findings demonstrate, without question, that the gap between official and actual PHEV fuel consumption and CO₂ emissions is significantly larger than for gasoline or conventional cars,” the expert stated. “Any policy changes concerning PHEVs should be made with utmost care and considering that data.”