🔗 Share this article

PHEVs release nearly 5x more global warming pollution than official data indicate, according to a new analysis.

Growing Gap Between Official and Real-World CO2 Output

Statistics shows that PHEVs release just one-fifth lower CO₂ than traditional gas and diesel vehicles, according to analysis conducted by a advocacy organization. This differs sharply with lab tests, which assumed a 75% decrease in pollution.

Analysts examined data from in-vehicle energy use monitors of 800,000 cars sold in Europe from 2021 and 2023. The team found that actual CO₂ output from PHEVs in 2023 were nearly five times higher than official estimates, increased from 3.5 times in 2021.

“Actual CO2 output are rising, while official figures are decreasing,” said a senior researcher involved in the report. “This gap is widening and creates a significant issue. Consequently, PHEVs emit almost as heavily as gasoline vehicles.”

Key Factors Behind the Discrepancy

Analysts attributed most of the difference to overestimates of the “electric driving share” – the percentage of kilometers driven in battery power compared to overall mileage. The team determined that only 27% of driving was completed in EV mode, whereas official assumptions assumed over four-fifths.

Even, when running in EV mode, pollution amounts were well above lab projections. That occurred because electric motors were not strong sufficient to function alone, resulting to engines burning gasoline for nearly a third of the travel covered in electric mode.

Regulatory and Economic Implications

According to estimates, the underestimation of PHEV emissions enabled several major carmaker companies to avoid more than €5bn in fines from 2021 and 2023, by artificially easing adherence with European Union average fleet CO₂ targets.

Furthermore, owners of PHEVs would pay approximately €500 more per year in running costs than is assumed under laboratory conditions.

“The strong claims that automakers like to make about their plug-in hybrid cars are clearly far from the truth,” stated a automotive expert. “Buyers are being duped into thinking that by buying a PHEV, they are helping the environment and cutting costs. Actually, PHEVs are little improved than regular petrol and diesel cars in terms of energy consumption, CO₂ emissions, and running expenses.”

Political Debate and Automotive Lobbying

Hybrid vehicles have lately been brought back into political debates as automakers have pressed the European Union to relax CO₂ targets. A planned ban on sales of new internal combustion vehicles in 2035 has faced heavy pressure from the automotive sector and resistance from member states with significant automotive manufacturing.

Several senior politicians have proposed PHEVs as a possible “compromise” solution to introduce in the legislation.

An external energy policy specialist, who was not involved with the study, described the report a “very useful contribution” after a long period in which parts of the automotive industry argued there was insufficient data to accurately evaluate real-world CO2 output.

“These findings show, beyond any doubt, that the gap between official and real-world PHEV fuel consumption and CO₂ output is much, much larger than for gasoline or diesel cars,” the expert said. “Any regulatory changes regarding PHEVs should be implemented with extreme caution and considering that evidence.”