🔗 Share this article

Plug-in hybrid cars release almost five times greater planet-heating pollution than lab-reported figures show, as per a new report.

Widening Discrepancy In Official and Actual Emissions

Statistics shows that PHEVs emit just one-fifth less CO₂ than traditional petrol and diesel vehicles, according to analysis carried out by a non-profit group. That contrasts significantly with lab estimates, which suggested a 75% reduction in pollution.

Analysts examined information from onboard fuel consumption meters of eight hundred thousand cars registered in Europe between 2021 and 2023. The team discovered that actual CO₂ output from PHEVs in 2023 were nearly five times greater than lab estimates, increased from three and a half times in 2021.

“Actual emissions are increasing, while official emissions are falling,” said a lead researcher participating in the report. “That gap is growing and creates a serious issue. As a result, PHEVs pollute almost as much as gasoline cars.”

Key Factors Driving the Emissions Gap

Researchers attributed the majority of the difference to inflated estimates of the “electric driving share” – the percentage of miles driven in electric power relative to overall mileage. They determined that only a quarter of driving was completed in electric mode, while official estimates suggested 84%.

Even, when running in electric mode, emission amounts were significantly higher than official projections. This happened because electric motors were not strong enough to operate alone, resulting to engines using fossil fuels for almost a third of the travel covered in electric mode.

Regulatory and Financial Consequences

Based on calculations, the lowballing of PHEV CO2 output enabled four large carmaker companies to avoid more than €5bn in fines from 2021 and 2023, by falsely simplifying compliance with European Union fleet-average CO₂ targets.

Additionally, owners of PHEVs could pay about €500 more annually in running expenses than would be assumed under lab conditions.

“The bold claims that automakers like to make about their plug-in hybrid cars are clearly far from the truth,” stated a transport expert. “Consumers are being duped into believing that by buying a PHEV, they are benefiting the environment and cutting costs. Actually, PHEVs are only slightly better than regular gas and diesel vehicles in terms of fuel consumption, CO₂ emissions, and running costs.”

Political Discussion and Automotive Lobbying

Hybrid cars have lately been brought again into policy debates as carmakers have pressed the European Union to weaken CO₂ targets. A planned prohibition on new combustion engine vehicles in 2035 has faced heavy pressure from the automotive sector and opposition from EU countries with significant car manufacturing.

Several high-level politicians have suggested PHEVs as a possible “compromise” option to include in the regulation.

An independent energy economics specialist, who was not involved with the study, called the report a “highly valuable contribution” after a long period in which parts of the car sector argued there was insufficient data to accurately assess real-world CO2 output.

“The results demonstrate, beyond any doubt, that the gap in official and actual PHEV energy use and CO₂ emissions is significantly larger than for gasoline or diesel vehicles,” the expert stated. “Any policy adjustments concerning PHEVs should be made with utmost care and in the light of this evidence.”