🔗 Share this article

PHEVs release almost five times greater planet-heating pollution than official figures indicate, as per a new analysis.

Widening Gap Between Lab and Actual CO2 Output

Statistics shows that PHEVs emit just 19% lower CO₂ than traditional petrol and diesel cars, based on research conducted by a non-profit organization. This contrasts significantly with lab tests, which suggested a 75% reduction in pollution.

Analysts studied information from onboard fuel consumption meters of 800,000 vehicles sold in the EU between 2021 and 2023. The team discovered that real-world CO₂ output from PHEVs in 2023 were nearly five times greater than official figures, up from three and a half times in 2021.

“Real-world CO2 output are increasing, while official emissions are falling,” stated a senior researcher involved in the report. “That discrepancy is growing and creates a serious issue. As a result, PHEVs emit almost as heavily as petrol cars.”

Key Reasons Driving the Emissions Gap

Analysts attributed the majority of the gap to inflated estimates of the “electric driving share” – the ratio of miles driven in electric mode compared to overall mileage. They determined that just a quarter of driving was done in electric mode, while lab assumptions assumed 84%.

Additionally, when operating in electric mode, emission levels were significantly higher than official projections. That happened because electric motors were not strong sufficient to function independently, resulting to engines using fossil fuels for almost a third of the travel covered in electric mode.

Policy and Economic Implications

According to calculations, the lowballing of PHEV emissions enabled four large carmaker groups to avoid more than €5bn in penalties from 2021 and 2023, by falsely simplifying compliance with EU average fleet CO₂ targets.

Furthermore, owners of PHEVs could pay about €500 more per year in running costs than would be estimated under laboratory tests.

“The strong statements that manufacturers like to make about their plug-in hybrid cars are clearly way off the truth,” stated a transport expert. “Buyers are being duped into believing that by purchasing a PHEV, they are helping the planet and cutting costs. In reality, PHEVs are only slightly better than regular gas and diesel cars in terms of energy consumption, CO₂ emissions, and running expenses.”

Policy Debate and Industry Pressure

Hybrid vehicles have lately been brought back into policy discussions as automakers have pressed the EU to relax CO₂ targets. A planned ban on sales of new internal combustion cars in 2035 has faced heavy pressure from the automotive industry and resistance from member states with significant car manufacturing.

Some senior politicians have proposed PHEVs as a possible “compromise” option to include in the regulation.

An external energy economics expert, who was unaffiliated with the research, described the report a “highly valuable addition” after a long period in which segments of the car industry argued there was too little information to accurately assess actual CO2 output.

“These findings demonstrate, without question, that the gap between official and actual PHEV fuel consumption and CO₂ emissions is much, much larger than for petrol or diesel cars,” the expert said. “All regulatory adjustments regarding PHEVs should be made with extreme care and in the light of this evidence.”