Plug-in Hybrid electric Vehicles Emit Nearly as Heavily as Petrol Vehicles, Report Finds

Plug-in hybrid cars emit nearly five times more global warming emissions than lab-reported data show, according to a recent analysis.

Widening Discrepancy Between Official and Real-World Emissions

Data shows that PHEVs release only one-fifth less CO₂ than traditional petrol and diesel vehicles, based on analysis carried out by a advocacy organization. That contrasts significantly with laboratory estimates, which suggested a 75% reduction in pollution.

Researchers studied information from in-vehicle fuel consumption meters of 800,000 cars sold in Europe between 2021 and 2023. The team discovered 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 CO2 output are rising, while lab-reported figures are decreasing,” stated a lead researcher participating in the study. “This gap is growing and poses a significant issue. As a result, PHEVs emit almost as much as gasoline cars.”

Primary Factors Driving the Discrepancy

Analysts attributed the majority of the difference to inflated estimates of the “electric driving share” – the ratio of miles driven in electric mode compared to overall distance. The team determined that only a quarter of travel was done in electric mode, whereas official estimates suggested 84%.

Even, when running in EV mode, pollution levels were well above lab estimates. This happened because electric motors were not strong sufficient to function alone, leading to engines burning gasoline for almost a third of the distance completed in electric mode.

Regulatory and Economic Consequences

According to estimates, the lowballing of PHEV emissions allowed four large carmaker companies to avoid over €5bn in penalties between 2021 and 2023, by falsely simplifying compliance with European Union average fleet CO₂ targets.

Furthermore, owners of PHEVs could pay about €500 more per year in running expenses than is estimated under lab tests.

“The bold statements that automakers often promote about their plug-in hybrid vehicles are clearly way off the mark,” stated a automotive expert. “Buyers are being misled into believing that by buying a PHEV, they are helping the planet and saving costs. In reality, PHEVs are only slightly improved than regular petrol and diesel cars in terms of fuel consumption, CO₂ emissions, and running expenses.”

Political Discussion and Automotive Pressure

Plug-in hybrid cars have lately been drawn back into political discussions as carmakers have pressed the European Union to weaken 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 significant car industries.

Several senior politicians have proposed PHEVs as a possible “flexibility” option to introduce in the regulation.

An external energy economics expert, who was unaffiliated with the study, described the report a “very useful contribution” after years in which segments of the automotive sector claimed there was insufficient information to properly evaluate real-world CO2 output.

“These findings demonstrate, beyond any doubt, that the gap between lab and real-world PHEV fuel consumption and CO₂ emissions is significantly larger than for petrol or conventional vehicles,” they stated. “Any policy changes regarding PHEVs should be implemented with extreme caution and in the light of that evidence.”