Plug-in Hybrid Vehicles Pollute Almost as Much as Petrol Cars, Report Finds

Plug-in hybrid electric vehicles release almost five times greater planet-heating emissions than official figures show, according to a recent report.

Growing Gap Between Official and Real-World CO2 Output

Statistics reveals that PHEVs release just one-fifth less CO₂ than traditional gas and diesel vehicles, according to analysis carried out by a advocacy organization. This differs sharply with laboratory tests, which suggested a 75% decrease in emissions.

Analysts examined data from in-vehicle fuel consumption meters of 800,000 cars registered in Europe between 2021 and 2023. They found that actual CO₂ output from PHEVs in 2023 were nearly five times greater than official figures, up from 3.5 times in 2021.

“Real-world emissions are increasing, while lab-reported emissions are falling,” stated a senior researcher participating in the report. “That gap is growing and poses a significant issue. As a result, PHEVs pollute almost as heavily as gasoline cars.”

Primary Factors Driving the Emissions Gap

Analysts attributed the majority of the gap to inflated estimates of the “electric driving share” – the ratio of miles driven in electric power compared to overall mileage. The team found that only 27% of driving was done in electric mode, while official assumptions assumed 84%.

Additionally, when operating in EV mode, emission levels were well above lab estimates. This occurred because EV motors were not strong sufficient to function independently, resulting to engines using gasoline for nearly one-third of the travel covered in EV mode.

Policy and Financial Consequences

Based on calculations, the lowballing of PHEV CO2 output allowed several large carmaker companies to avoid more than €5bn in penalties between 2021 and 2023, by artificially simplifying compliance with EU fleet-average CO₂ targets.

Furthermore, owners of PHEVs would spend about €500 extra per year in running costs than is estimated under lab tests.

“The strong claims that manufacturers often promote about their plug-in hybrid cars are obviously far from the truth,” commented a automotive expert. “Consumers are being misled into believing that by purchasing a PHEV, they are benefiting the planet and saving money. Actually, PHEVs are little improved than regular gas and diesel cars in terms of fuel consumption, CO₂ production, and operating expenses.”

Policy Debate and Automotive Lobbying

Hybrid cars have lately been drawn again into political discussions as carmakers have pressed the European Union to relax CO₂ targets. A proposed prohibition on sales of new internal combustion vehicles in 2035 has faced heavy pressure from the automotive sector and resistance from EU countries with large car manufacturing.

Some high-level officials have suggested PHEVs as a possible “flexibility” solution to include in the legislation.

An independent energy policy specialist, who was unaffiliated with the study, described the report a “very useful addition” after years in which segments of the car sector claimed there was too little information to properly evaluate actual emissions.

“These findings show, without question, that the difference in lab and real-world PHEV fuel consumption and CO₂ emissions is much, much larger than for gasoline or conventional vehicles,” they said. “All regulatory changes regarding PHEVs should be made with utmost care and in the light of this data.”