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PHEVs produce nearly 5x more planet-heating emissions than official figures indicate, as per a recent analysis.

Growing Discrepancy Between Official and Real-World Emissions

Statistics reveals that PHEVs emit only one-fifth less CO₂ than conventional petrol and diesel vehicles, based on analysis conducted by a advocacy organization. This differs sharply with laboratory estimates, which assumed a three-quarters reduction in emissions.

Analysts studied information from onboard energy use meters of 800,000 vehicles registered in Europe from 2021 and 2023. The team found that actual CO₂ output from PHEVs in 2023 were 4.9 times greater than official figures, increased from 3.5 times in 2021.

“Real-world CO2 output are increasing, while official emissions are decreasing,” stated a lead analyst participating in the study. “This discrepancy is growing and poses a significant problem. As a result, PHEVs pollute nearly as much as gasoline cars.”

Key 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 power relative to overall mileage. They found that only a quarter of driving was completed in EV mode, while lab assumptions assumed over four-fifths.

Additionally, when running in EV mode, emission amounts were significantly higher than lab estimates. That happened because electric motors were not strong sufficient to operate independently, resulting to engines burning fossil fuels for nearly one-third of the travel completed in electric mode.

Regulatory and Financial Consequences

Based on calculations, the underestimation of PHEV emissions enabled several major carmaker companies to escape more than €5bn in fines from 2021 and 2023, by artificially easing compliance with European Union fleet-average CO₂ targets.

Furthermore, drivers of PHEVs would pay about €500 more annually in operating costs than is assumed under laboratory tests.

“The strong claims that manufacturers often promote about their PHEV vehicles are obviously far from the truth,” commented a transport expert. “Buyers are being duped into thinking that by purchasing a PHEV, they are benefiting the planet and saving costs. Actually, PHEVs are little improved than standard petrol 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 policy debates as automakers have lobbied the EU to relax CO₂ targets. A planned prohibition on new internal combustion cars in 2035 has faced intense pressure from the automotive industry and opposition from member states with significant car manufacturing.

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

An external energy economics expert, who was not involved with the research, described the analysis a “highly valuable addition” after years in which parts of the car sector argued there was insufficient data to properly evaluate actual CO2 output.

“The results demonstrate, beyond any doubt, that the difference in lab and real-world PHEV energy use and CO₂ output is significantly larger than for gasoline or diesel cars,” the expert stated. “All regulatory changes concerning PHEVs should be implemented with utmost care and in the light of this evidence.”