Plug-in Hybrid electric Cars Emit Almost as Heavily as Gasoline Cars, Report Finds

PHEVs produce almost five times more planet-heating pollution than official figures show, according to a recent report.

Widening Gap Between Official and Actual Emissions

Data reveals that PHEVs release just 19% lower CO₂ than traditional gas and diesel cars, based on research carried out by a advocacy group. That differs significantly with lab estimates, which assumed a 75% reduction in pollution.

Analysts examined information from onboard fuel consumption monitors of 800,000 cars sold in the EU between 2021 and 2023. The team found that actual CO₂ output 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 falling,” stated a senior researcher participating in the report. “That gap is growing and poses a significant problem. Consequently, PHEVs pollute nearly as heavily as gasoline cars.”

Key Reasons Driving the Emissions Gap

Analysts linked the majority of the gap to inflated estimates of the “utility factor” – the percentage of miles driven in battery power compared to total mileage. The team found that just a quarter of travel was done in EV mode, whereas lab estimates assumed 84%.

Even, when operating in EV mode, pollution amounts were well above lab projections. That occurred because electric motors were not strong enough to function independently, leading to engines using fossil fuels for almost a third of the distance covered in EV mode.

Policy and Economic Consequences

According to calculations, the lowballing of PHEV emissions enabled four major carmaker groups to escape more than €5bn in fines from 2021 and 2023, by artificially easing compliance with European Union average fleet CO₂ standards.

Additionally, drivers of PHEVs could pay about €500 extra per year in running expenses than would be estimated under lab conditions.

“The bold statements that automakers like to make about their PHEV vehicles are obviously way off the mark,” stated a transport analyst. “Consumers are being misled into thinking that by purchasing a PHEV, they are benefiting the planet and cutting money. In reality, PHEVs are little improved than regular gas and diesel cars in terms of energy use, CO₂ production, and running expenses.”

Policy Debate and Automotive Lobbying

Hybrid vehicles have lately been brought back into policy discussions as automakers have pressed the EU to weaken CO₂ targets. A planned ban on sales of new combustion engine cars in 2035 has faced heavy lobbying from the automotive sector and opposition from member states with significant car industries.

Several senior officials have suggested plug-in hybrids as a possible “flexibility” option to introduce in the legislation.

An external 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 claimed there was insufficient data to accurately assess real-world emissions.

“These findings demonstrate, without question, that the difference in official and real-world PHEV energy use and CO₂ emissions is much, much larger than for gasoline or conventional cars,” the expert said. “Any policy adjustments regarding PHEVs should be made with extreme caution and considering this evidence.”