Plug-in Hybrid electric Cars Pollute Nearly as Heavily as Gasoline Vehicles, Study Finds

PHEVs release almost five times greater planet-heating pollution than official data show, as per a recent analysis.

Growing Gap In Lab and Actual Emissions

Data reveals that PHEVs release only 19% less CO₂ than traditional gas and diesel vehicles, according to research conducted by a non-profit group. This differs significantly with lab tests, which suggested a 75% decrease in pollution.

Researchers examined data from in-vehicle fuel consumption monitors of 800,000 vehicles sold in Europe between 2021 and 2023. The team found that actual CO₂ output from PHEVs in 2023 were nearly five times greater than lab estimates, increased from 3.5 times in 2021.

“Actual emissions are increasing, while official figures are falling,” stated a senior analyst participating in the report. “That discrepancy is widening and creates a serious issue. Consequently, PHEVs emit almost as heavily as gasoline cars.”

Primary Reasons Behind the Emissions Gap

Researchers attributed the majority of the difference to inflated estimates of the “utility factor” – the ratio of kilometers driven in electric power compared to overall mileage. The team determined that just 27% of travel was completed in EV mode, while lab estimates suggested 84%.

Even, when running in EV mode, pollution amounts were well above lab estimates. This occurred because EV motors were not strong sufficient to operate alone, resulting to combustion motors using fossil fuels for almost one-third of the distance completed in electric mode.

Policy and Financial Consequences

According to estimates, the lowballing of PHEV emissions enabled several large automaker groups to avoid more than €5bn in fines from 2021 and 2023, by artificially simplifying adherence with European Union fleet-average CO₂ targets.

Furthermore, drivers of PHEVs would spend about €500 more per year in running expenses than would be estimated under lab tests.

“The strong claims that automakers like to make about their plug-in hybrid cars are clearly far from the mark,” stated a transport expert. “Buyers are being duped into thinking that by buying a PHEV, they are helping the planet and cutting costs. Actually, PHEVs are only slightly improved than standard gas and diesel vehicles in terms of energy consumption, CO₂ production, and operating costs.”

Political Debate and Automotive Lobbying

Plug-in hybrid cars have lately been drawn again into policy debates as automakers have pressed the EU to weaken CO₂ standards. A planned ban on sales of new combustion engine vehicles in 2035 has faced heavy pressure from the automotive sector and resistance from EU countries with large automotive manufacturing.

Some high-level politicians have proposed plug-in hybrids as a possible “compromise” solution to include in the regulation.

An external energy economics specialist, who was unaffiliated with the study, called the analysis a “very useful contribution” after years in which segments of the car sector argued there was insufficient information to properly assess real-world CO2 output.

“The results demonstrate, beyond any doubt, that the gap in official and real-world PHEV energy use and CO₂ emissions is much, much larger than for gasoline or conventional vehicles,” the expert stated. “All regulatory adjustments regarding PHEVs should be made with utmost caution and considering this evidence.”