🔗 Share this article

Plug-in hybrid cars emit nearly five times greater global warming emissions than official figures indicate, as per a recent report.

Growing Gap In Official and Actual Emissions

Data shows that PHEVs release only 19% less CO₂ than conventional petrol and diesel vehicles, according to research carried out by a advocacy group. This differs sharply with laboratory estimates, which assumed a 75% reduction in pollution.

Analysts studied information from in-vehicle energy use meters of eight hundred thousand vehicles registered in Europe from 2021 and 2023. They found that actual CO₂ output from PHEVs in 2023 were 4.9 times higher than official figures, up from three and a half times in 2021.

“Actual CO2 output are increasing, while official emissions are decreasing,” said a senior researcher participating in the report. “This gap is widening and poses a serious issue. As a result, PHEVs pollute nearly as much as petrol cars.”

Primary Factors Driving the Emissions Gap

Analysts attributed most of the gap to inflated estimates of the “utility factor” – the percentage of miles travelled in electric mode relative to total distance. They found that just a quarter of travel was done in electric mode, whereas official estimates assumed over four-fifths.

Even, when running in electric mode, emission levels were significantly higher than official estimates. That happened because electric motors were not strong enough to operate independently, resulting to engines using gasoline for nearly one-third of the distance covered in electric mode.

Policy and Financial Implications

According to calculations, the underestimation of PHEV CO2 output enabled several major carmaker companies to avoid more than €5bn in penalties from 2021 and 2023, by falsely easing adherence with EU average fleet CO₂ standards.

Furthermore, drivers of PHEVs could spend approximately €500 extra annually in operating expenses than is estimated under laboratory conditions.

“The bold statements that automakers often promote about their PHEV cars are obviously way off the truth,” commented a automotive analyst. “Buyers are being misled into believing that by buying a PHEV, they are helping the environment and saving costs. In reality, PHEVs are only slightly improved than regular gas and diesel vehicles in terms of fuel consumption, CO₂ production, and running costs.”

Policy Debate and Industry Lobbying

Plug-in hybrid cars have recently been drawn back into policy discussions as carmakers have lobbied the EU to relax CO₂ standards. A proposed prohibition on sales of new combustion engine cars in 2035 has faced intense lobbying from the automotive industry and opposition from member states with large automotive industries.

Some senior officials have proposed PHEVs as a potential “compromise” solution to include in the legislation.

One external energy policy expert, who was unaffiliated with the study, described the analysis a “very useful addition” after a long period in which segments of the automotive sector argued there was insufficient data to accurately assess actual CO2 output.

“These findings demonstrate, without question, that the gap in official and actual PHEV fuel consumption and CO₂ emissions is significantly larger than for petrol or conventional vehicles,” the expert stated. “Any regulatory adjustments concerning PHEVs should be implemented with extreme care and considering this data.”