Plug in Hybrid Vehicles Emit Almost as Much as Petrol Cars, Report Reveals

Plug-in hybrid electric vehicles produce nearly five times greater planet-heating emissions than lab-reported figures indicate, according to a recent analysis.

Widening Gap In Lab and Real-World Emissions

Data reveals that PHEVs emit just 19% lower CO₂ than conventional gas and diesel vehicles, according to analysis carried out by a non-profit organization. This differs significantly with laboratory tests, which suggested a 75% reduction in emissions.

Analysts studied information from onboard energy use meters of 800,000 vehicles registered in Europe between 2021 and 2023. The team discovered that real-world CO₂ emissions from PHEVs in 2023 were nearly five times higher than lab estimates, increased from 3.5 times in 2021.

“Actual emissions are increasing, while official figures are falling,” stated a senior researcher participating in the report. “That discrepancy is growing and creates a serious problem. Consequently, PHEVs pollute nearly as much as gasoline vehicles.”

Primary Factors Driving the Discrepancy

Analysts attributed the majority of the gap to inflated estimates of the “utility factor” – the percentage of miles driven in electric mode relative to total distance. They found that only a quarter of driving was completed in EV mode, whereas lab estimates assumed over four-fifths.

Additionally, when running in EV mode, emission levels were well above official projections. This happened because EV motors were insufficiently powerful enough to operate alone, resulting to engines burning gasoline for nearly a third of the travel completed in EV mode.

Policy and Economic Consequences

Based on estimates, the lowballing of PHEV CO2 output allowed four large automaker groups to escape more than €5bn in fines between 2021 and 2023, by artificially easing compliance with EU fleet-average CO₂ standards.

Additionally, owners of PHEVs would spend approximately €500 extra per year in operating expenses than is assumed under lab conditions.

“The strong statements that automakers like to make about their plug-in hybrid cars are clearly far from the truth,” commented a automotive analyst. “Consumers are being duped into believing that by purchasing a PHEV, they are helping the planet and saving money. Actually, PHEVs are only slightly better than regular petrol and diesel vehicles in terms of energy use, CO₂ emissions, and operating costs.”

Political Discussion and Industry Pressure

Plug-in hybrid vehicles have lately been drawn back into policy debates as carmakers have pressed the EU to weaken CO₂ targets. A proposed ban on new combustion engine cars in 2035 has faced heavy pressure from the car industry and opposition from member states with large car industries.

Some high-level officials have suggested PHEVs as a possible “compromise” option to include in the legislation.

An external energy economics expert, who was not involved with the study, called the analysis a “highly valuable addition” after a long period in which segments of the automotive sector argued there was too little information to properly assess real-world emissions.

“These findings show, beyond any doubt, that the difference between lab and real-world PHEV fuel consumption and CO₂ output is significantly greater than for petrol or diesel vehicles,” they said. “All policy changes regarding PHEVs should be made with extreme caution and considering that data.”