🔗 Share this article

Plug-in hybrid cars produce almost 5x greater planet-heating pollution than lab-reported figures show, according to a recent report.

Widening Discrepancy Between Lab and Real-World CO2 Output

Statistics shows that PHEVs emit only 19% less CO₂ than conventional gas and diesel vehicles, according to analysis conducted by a advocacy group. That differs significantly with laboratory estimates, which assumed a three-quarters decrease in emissions.

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

“Actual emissions are increasing, while official emissions are decreasing,” stated a senior researcher participating in the study. “That gap is growing and creates a serious issue. Consequently, PHEVs pollute nearly as much as gasoline cars.”

Key Factors Driving the Emissions Gap

Analysts linked the majority of the difference to overestimates of the “electric driving share” – the ratio of kilometers travelled in battery power compared to overall mileage. The team found that only a quarter of driving was done in electric mode, while official assumptions assumed over four-fifths.

Even, when operating in electric mode, pollution levels were significantly higher than lab projections. That happened because electric motors were insufficiently powerful sufficient to operate alone, leading to engines burning fossil fuels for nearly one-third of the distance completed in EV mode.

Regulatory and Economic Implications

According to calculations, the underestimation of PHEV CO2 output enabled several major carmaker groups to avoid over €5bn in penalties from 2021 and 2023, by artificially simplifying compliance with EU fleet-average CO₂ targets.

Furthermore, drivers of PHEVs could pay approximately €500 extra annually in running expenses than would be assumed under lab tests.

“The bold statements that automakers like to make about their PHEV vehicles are obviously way off the mark,” commented a automotive analyst. “Buyers are being misled into thinking that by purchasing a PHEV, they are helping the planet and saving money. Actually, PHEVs are only slightly improved than regular gas and diesel cars in terms of energy consumption, CO₂ production, and running expenses.”

Political Discussion and Industry Lobbying

Plug-in hybrid vehicles have lately been drawn back into political debates as carmakers have pressed the EU to relax CO₂ standards. A proposed prohibition on new internal combustion cars in 2035 has faced intense pressure from the automotive industry and opposition from member states with large car industries.

Several senior officials have suggested plug-in hybrids as a possible “compromise” option to introduce in the legislation.

One independent energy economics specialist, who was unaffiliated with the research, described the analysis a “very useful addition” after a long period in which segments of the car industry argued there was insufficient data to properly assess actual emissions.

“These findings show, without question, that the gap in official and actual PHEV fuel consumption and CO₂ emissions is much, much greater than for petrol or diesel cars,” they stated. “Any regulatory adjustments regarding PHEVs should be implemented with extreme caution and considering that evidence.”