Plug-in Hybrid Vehicles Pollute Nearly as Much as Gasoline Vehicles, Report Reveals

PHEVs produce nearly 5x more global warming pollution than official figures show, as per a new analysis.

Widening Discrepancy In Lab and Actual CO2 Output

Statistics reveals that PHEVs release only 19% less CO₂ than traditional petrol and diesel cars, according to research carried out by a advocacy organization. This differs sharply with lab estimates, which suggested a three-quarters decrease in emissions.

Researchers examined information from onboard energy use 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 greater than official estimates, up from 3.5 times in 2021.

“Actual CO2 output are increasing, while lab-reported figures are falling,” said a lead analyst involved in the study. “That discrepancy is widening and poses a significant issue. Consequently, PHEVs pollute almost as much as gasoline vehicles.”

Primary Reasons Driving the Discrepancy

Analysts attributed most of the gap to overestimates of the “electric driving share” – the percentage of miles travelled in battery power relative to total mileage. The team found that only 27% of driving was completed in electric mode, while lab assumptions suggested 84%.

Even, when operating in electric mode, emission levels were significantly higher than lab estimates. This occurred because electric motors were insufficiently powerful enough to function independently, leading to engines using fossil fuels for almost a third of the distance completed in EV mode.

Policy and Economic Consequences

According to estimates, the lowballing of PHEV emissions enabled four large carmaker companies to avoid over €5bn in fines between 2021 and 2023, by falsely easing compliance with European Union fleet-average CO₂ standards.

Additionally, owners of PHEVs could pay about €500 more per year in running costs than is assumed under laboratory tests.

“The bold claims that automakers often promote about their PHEV vehicles are obviously way off the truth,” commented a automotive analyst. “Consumers are being misled into thinking that by buying a PHEV, they are helping the planet and cutting money. In reality, PHEVs are little improved than standard petrol and diesel vehicles in terms of fuel use, CO₂ emissions, and operating costs.”

Political Discussion and Industry Pressure

Hybrid cars have lately been brought again into policy discussions as automakers have pressed the EU to relax CO₂ targets. A planned ban on new combustion engine vehicles in 2035 has faced heavy pressure from the car sector and opposition from EU countries with large automotive industries.

Several senior politicians have proposed PHEVs as a potential “compromise” solution to include in the regulation.

One independent energy economics specialist, who was unaffiliated with the study, described the analysis a “very useful contribution” after years in which parts of the automotive sector claimed there was too little information to accurately evaluate real-world CO2 output.

“These findings show, without question, that the gap between official and real-world PHEV energy use and CO₂ output is significantly larger than for gasoline or diesel cars,” the expert stated. “Any regulatory adjustments concerning PHEVs should be made with utmost care and in the light of that evidence.”