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PHEVs emit nearly five times more planet-heating pollution than official figures show, according to a recent analysis.

Growing Gap In Lab and Real-World CO2 Output

Statistics shows that PHEVs emit just one-fifth less CO₂ than conventional gas and diesel cars, according to research carried out by a advocacy group. That contrasts sharply with lab tests, which suggested a 75% decrease in pollution.

Analysts studied information from onboard fuel consumption meters of eight hundred thousand cars sold in the EU between 2021 and 2023. They found that real-world CO₂ output from PHEVs in 2023 were nearly five times higher than official estimates, increased from 3.5 times in 2021.

“Real-world emissions are rising, while lab-reported figures are decreasing,” said a lead researcher involved in the report. “This gap is growing and creates a significant problem. Consequently, PHEVs pollute nearly as much as petrol vehicles.”

Key Reasons Behind the Discrepancy

Analysts attributed most of the difference to overestimates of the “utility factor” – the percentage of miles travelled in electric power compared to overall mileage. The team found that just 27% of travel was completed in EV mode, whereas official assumptions assumed 84%.

Even, when operating in EV mode, pollution levels were well above lab estimates. This occurred because electric motors were not strong sufficient to function independently, resulting to engines burning gasoline for nearly one-third of the distance completed in electric mode.

Policy and Financial Consequences

Based on estimates, the underestimation of PHEV emissions enabled several major carmaker companies to escape over €5bn in penalties between 2021 and 2023, by falsely easing adherence with EU average fleet CO₂ targets.

Additionally, drivers of PHEVs could spend about €500 extra annually in running costs than would be assumed under laboratory conditions.

“The strong claims that manufacturers often promote about their plug-in hybrid vehicles are obviously way off the truth,” commented a automotive expert. “Buyers are being misled into believing that by purchasing a PHEV, they are benefiting the planet and saving costs. In reality, PHEVs are only slightly improved than regular gas and diesel vehicles in terms of energy use, CO₂ emissions, and operating expenses.”

Political Debate and Automotive Pressure

Hybrid cars have lately been drawn again into political debates as automakers have pressed the EU to relax CO₂ targets. A planned prohibition on sales of new combustion engine vehicles in 2035 has faced intense pressure from the automotive industry and resistance from member states with large automotive industries.

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

One independent energy economics expert, who was unaffiliated with the research, called the analysis a “very useful contribution” after years in which segments of the car sector claimed there was too little data to properly evaluate actual CO2 output.

“The results show, beyond any doubt, that the difference in official and real-world PHEV fuel consumption and CO₂ emissions is much, much larger than for petrol or conventional cars,” the expert stated. “All policy changes regarding PHEVs should be made with utmost caution and in the light of that evidence.”