Plug in Hybrid electric Vehicles Pollute Almost as Much as Gasoline Vehicles, Report Finds

Plug-in hybrid cars emit nearly five times more global warming emissions than official data indicate, according to a recent report.

Growing Gap Between Official and Actual CO2 Output

Statistics reveals that PHEVs emit just one-fifth lower CO₂ than conventional gas and diesel vehicles, based on research conducted by a non-profit group. This contrasts sharply with lab tests, which suggested a 75% reduction in emissions.

Analysts examined data from in-vehicle energy use meters of 800,000 cars registered in the EU between 2021 and 2023. They discovered that real-world CO₂ output from PHEVs in 2023 were nearly five times greater than lab estimates, increased from three and a half times in 2021.

“Actual CO2 output are rising, while lab-reported emissions are falling,” said a lead analyst involved in the study. “That discrepancy is widening and poses a significant problem. As a result, PHEVs emit almost as much as petrol vehicles.”

Key Factors Behind the Emissions Gap

Analysts attributed the majority of the gap to overestimates of the “electric driving share” – the ratio of miles travelled in electric mode relative to overall mileage. The team determined that only a quarter of driving was completed in electric mode, while lab estimates suggested over four-fifths.

Additionally, when operating in electric mode, emission levels were significantly higher than lab projections. This happened because electric motors were not strong enough to operate alone, resulting to engines using gasoline for almost a third of the distance covered in electric mode.

Policy and Financial Consequences

According to estimates, the lowballing of PHEV CO2 output allowed four major automaker groups to escape more than €5bn in penalties from 2021 and 2023, by falsely simplifying compliance with EU fleet-average CO₂ standards.

Additionally, owners of PHEVs would spend about €500 extra annually in operating costs than is estimated under laboratory tests.

“The bold claims that automakers like to make about their plug-in hybrid cars are obviously way off the truth,” commented a automotive expert. “Consumers are being misled into believing that by buying a PHEV, they are helping the environment and saving costs. Actually, PHEVs are only slightly better than regular gas and diesel cars in terms of energy use, CO₂ production, and running costs.”

Political Discussion and Industry Pressure

Hybrid cars have recently been drawn back into political debates as automakers have pressed the EU to weaken CO₂ standards. A planned prohibition on new combustion engine cars in 2035 has faced heavy pressure from the car sector and opposition from EU countries with large car industries.

Some senior politicians have proposed plug-in hybrids as a possible “flexibility” option to introduce in the regulation.

An external energy policy specialist, who was unaffiliated with the research, called the report a “very useful contribution” after years in which parts of the automotive sector argued there was insufficient data to properly assess actual CO2 output.

“The results demonstrate, without question, that the difference between official and actual PHEV energy use and CO₂ output is much, much greater than for gasoline or conventional cars,” they stated. “All policy adjustments concerning PHEVs should be made with utmost care and considering this data.”