Plug-in Hybrid electric Vehicles Pollute Almost as Much as Petrol Vehicles, Study Reveals

Plug-in hybrid cars emit almost five times greater global warming emissions than official figures indicate, according to a recent report.

Widening Discrepancy Between Lab and Actual Emissions

Data reveals that PHEVs release only one-fifth less CO₂ than conventional petrol and diesel vehicles, according to research conducted by a non-profit organization. This contrasts significantly with laboratory estimates, which assumed a 75% reduction in emissions.

Analysts studied data from onboard energy use monitors of 800,000 cars registered in the EU between 2021 and 2023. They found that actual CO₂ output from PHEVs in 2023 were nearly five times higher than official estimates, up from 3.5 times in 2021.

“Actual emissions are rising, while official emissions are falling,” stated a senior researcher participating in the report. “That gap is widening and poses a serious issue. As a result, PHEVs emit nearly as heavily as gasoline vehicles.”

Key Factors Behind the Emissions Gap

Analysts attributed the majority of the gap to inflated estimates of the “electric driving share” – the percentage of kilometers travelled in battery mode relative to overall mileage. The team found that just a quarter of driving was done in EV mode, whereas lab assumptions suggested over four-fifths.

Even, when running in electric mode, pollution amounts were well above lab projections. This occurred because EV motors were not strong sufficient to operate independently, resulting to combustion motors burning gasoline for almost a third of the distance covered in electric mode.

Policy and Economic Consequences

Based on estimates, the lowballing of PHEV CO2 output enabled four large automaker companies to avoid over €5bn in fines between 2021 and 2023, by falsely easing compliance with EU average fleet CO₂ standards.

Furthermore, owners of PHEVs would pay about €500 more per year in operating costs than would be assumed under lab conditions.

“The bold statements that automakers often promote about their PHEV cars are clearly far from the truth,” commented a automotive expert. “Buyers are being misled into believing that by purchasing a PHEV, they are benefiting the environment and saving costs. Actually, PHEVs are little better than regular gas and diesel vehicles in terms of fuel use, CO₂ production, and running costs.”

Policy Discussion and Industry Pressure

Hybrid cars have recently been brought back into policy discussions as carmakers have lobbied the European Union to weaken CO₂ targets. A planned ban on sales of new internal combustion vehicles in 2035 has faced heavy pressure from the car sector and resistance from member states with large automotive manufacturing.

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

One independent energy policy specialist, who was not involved with the study, described the analysis a “very useful addition” after years in which parts of the car industry claimed there was too little data to properly evaluate real-world emissions.

“These findings show, beyond any doubt, that the difference between lab and real-world PHEV fuel consumption and CO₂ output is much, much larger than for petrol or diesel vehicles,” the expert stated. “Any regulatory adjustments regarding PHEVs should be made with utmost care and considering this evidence.”