🔗 Share this article

PHEVs release nearly five times more global warming pollution than lab-reported data show, as per a recent report.

Growing Gap Between Official and Actual Emissions

Statistics shows that PHEVs release just 19% lower CO₂ than traditional gas and diesel cars, according to analysis conducted by a non-profit group. This differs sharply with laboratory tests, which assumed a 75% decrease in pollution.

Researchers studied data from in-vehicle fuel consumption monitors of eight hundred thousand cars registered in the EU between 2021 and 2023. The team discovered that actual CO₂ emissions from PHEVs in 2023 were 4.9 times higher than lab figures, up from three and a half times in 2021.

“Actual emissions are increasing, while lab-reported figures are decreasing,” stated a lead researcher involved in the report. “That discrepancy is widening and poses a serious issue. As a result, PHEVs pollute almost as heavily as petrol vehicles.”

Primary Factors Behind the Emissions Gap

Researchers attributed most of the difference to overestimates of the “utility factor” – the percentage of kilometers driven in electric power compared to overall distance. They found that only a quarter of driving was done in EV mode, whereas lab estimates suggested 84%.

Even, when operating in EV mode, emission levels were significantly higher than official projections. That happened because EV motors were not strong enough to operate independently, resulting to combustion motors using fossil fuels for almost one-third of the travel completed in electric mode.

Regulatory and Economic Implications

According to calculations, the underestimation of PHEV CO2 output enabled four large automaker companies to avoid more than €5bn in fines from 2021 and 2023, by falsely simplifying compliance with EU average fleet CO₂ targets.

Additionally, drivers of PHEVs could pay approximately €500 more annually in running expenses than would be estimated under laboratory conditions.

“The bold claims that automakers often promote about their plug-in hybrid vehicles are clearly far from the mark,” stated a transport expert. “Consumers are being duped into thinking that by purchasing a PHEV, they are benefiting the planet and cutting costs. In reality, PHEVs are little improved than regular gas and diesel vehicles in terms of energy consumption, CO₂ production, and running costs.”

Policy Discussion and Industry Lobbying

Hybrid vehicles have lately been drawn back into policy debates as carmakers have lobbied the European Union to relax CO₂ standards. A planned prohibition on sales of new combustion engine cars in 2035 has faced heavy lobbying from the automotive sector and opposition from member states with large automotive industries.

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

One independent energy policy specialist, who was not involved with the study, called the analysis a “highly valuable contribution” after years in which segments of the car sector claimed there was insufficient data to properly assess actual emissions.

“The results show, beyond any doubt, that the gap between official and actual PHEV energy use and CO₂ emissions is much, much larger than for petrol or conventional vehicles,” they said. “All regulatory changes concerning PHEVs should be implemented with extreme caution and considering this data.”