🔗 Share this article

PHEVs release nearly 5x greater global warming emissions than lab-reported figures show, according to a recent report.

Widening Gap Between Lab and Actual Emissions

Statistics shows that PHEVs release just one-fifth lower CO₂ than conventional gas and diesel cars, based on analysis conducted by a non-profit group. That differs sharply with laboratory estimates, which assumed a 75% reduction in emissions.

Researchers studied data from onboard fuel consumption monitors of eight hundred thousand vehicles sold in the EU between 2021 and 2023. They found that actual CO₂ emissions from PHEVs in 2023 were nearly five times greater than lab estimates, increased from three and a half times in 2021.

“Actual emissions are rising, while official emissions are falling,” said a lead analyst involved in the study. “This discrepancy is widening and creates a significant issue. Consequently, PHEVs emit nearly as heavily as petrol cars.”

Key Reasons Behind the Discrepancy

Researchers attributed the majority of the difference to inflated estimates of the “utility factor” – the ratio of kilometers driven in battery power relative to overall distance. The team determined that just 27% of travel was completed in electric mode, whereas official assumptions suggested over four-fifths.

Additionally, when operating in EV mode, pollution levels were well above lab estimates. This occurred because EV motors were insufficiently powerful sufficient to function independently, resulting to combustion motors using gasoline for almost a third of the distance completed in EV mode.

Policy and Financial Implications

Based on estimates, the underestimation of PHEV CO2 output enabled four large carmaker companies to avoid over €5bn in penalties from 2021 and 2023, by artificially easing compliance with EU average fleet CO₂ standards.

Furthermore, drivers of PHEVs could pay about €500 extra annually in operating costs than is estimated under lab tests.

“The strong claims that automakers like to make about their PHEV vehicles are clearly way off the truth,” commented a automotive expert. “Buyers are being misled into believing that by purchasing a PHEV, they are helping the planet and cutting costs. In reality, PHEVs are little better than regular petrol and diesel vehicles in terms of energy consumption, CO₂ emissions, and operating expenses.”

Policy Debate and Automotive Lobbying

Plug-in hybrid cars have recently been brought again into political discussions as automakers have pressed the EU to weaken CO₂ targets. A proposed prohibition on new internal combustion vehicles in 2035 has faced heavy pressure from the car sector and opposition from EU countries with significant car industries.

Some senior politicians have suggested plug-in hybrids as a potential “compromise” solution to introduce in the legislation.

One independent energy economics specialist, who was not involved with the research, called the report a “highly valuable contribution” after a long period in which parts of the car industry argued there was insufficient data to properly assess real-world emissions.

“These findings show, without question, that the difference in lab and actual PHEV fuel consumption and CO₂ emissions is significantly greater than for petrol or diesel cars,” the expert stated. “Any regulatory changes concerning PHEVs should be made with utmost care and considering this evidence.”