Plug-in Hybrid Vehicles Emit Nearly as Heavily as Gasoline Vehicles, Report Reveals

Plug-in hybrid electric vehicles release almost five times greater planet-heating pollution than lab-reported figures indicate, as per a recent report.

Growing Gap In Official and Actual CO2 Output

Data reveals that PHEVs release only one-fifth lower CO₂ than conventional petrol and diesel cars, based on analysis carried out by a non-profit organization. This contrasts significantly with lab estimates, which suggested a three-quarters decrease in pollution.

Researchers studied data from in-vehicle energy use meters of 800,000 vehicles registered in the EU between 2021 and 2023. The team found that real-world CO₂ emissions from PHEVs in 2023 were nearly five times higher than lab figures, up from 3.5 times in 2021.

“Actual emissions are rising, while lab-reported figures are decreasing,” stated a lead analyst involved in the study. “That discrepancy is growing and creates a significant problem. As a result, PHEVs emit almost as much as petrol cars.”

Primary Reasons Driving the Emissions Gap

Researchers attributed most of the gap to inflated estimates of the “electric driving share” – the ratio of miles driven in electric power relative to overall distance. The team determined that only a quarter of travel was done in EV mode, while official assumptions assumed over four-fifths.

Additionally, when operating in EV mode, emission amounts were well above official projections. This occurred because EV motors were not strong enough to operate alone, resulting to engines using fossil fuels for almost a third of the travel completed in EV mode.

Policy and Economic Implications

According to estimates, the lowballing of PHEV emissions enabled four large automaker companies to avoid over €5bn in penalties from 2021 and 2023, by falsely simplifying adherence with EU fleet-average CO₂ targets.

Additionally, owners of PHEVs would pay approximately €500 more annually in operating expenses than is assumed under lab conditions.

“The strong statements that manufacturers like to make about their plug-in hybrid vehicles are clearly far from the mark,” stated a transport expert. “Consumers are being duped into thinking that by buying a PHEV, they are helping the environment and cutting costs. In reality, PHEVs are little improved than standard gas and diesel cars in terms of energy use, CO₂ production, and running expenses.”

Policy Debate and Industry Pressure

Plug-in hybrid vehicles have lately been drawn back into policy debates as automakers have pressed the European Union to weaken CO₂ standards. A planned prohibition on sales of new combustion engine vehicles in 2035 has faced intense lobbying from the automotive sector and opposition from EU countries with significant car manufacturing.

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

One external energy economics expert, who was unaffiliated with the study, called the report a “very useful addition” after years in which parts of the car sector argued there was too little data to accurately assess real-world CO2 output.

“These findings demonstrate, without question, that the difference in official and actual PHEV fuel consumption and CO₂ output is significantly greater than for gasoline or conventional cars,” the expert said. “All policy changes concerning PHEVs should be implemented with utmost caution and considering that data.”