🔗 Share this article

Plug-in hybrid cars produce nearly five times more planet-heating emissions than lab-reported figures indicate, according to a new analysis.

Growing Discrepancy In Official and Real-World CO2 Output

Data reveals that PHEVs emit just 19% less CO₂ than traditional gas and diesel cars, based on analysis conducted by a advocacy group. This contrasts significantly with laboratory tests, which suggested a three-quarters reduction in emissions.

Analysts studied information from in-vehicle energy use meters of eight hundred thousand cars sold in Europe from 2021 and 2023. They found that real-world CO₂ output from PHEVs in 2023 were 4.9 times greater than lab estimates, increased from three and a half times in 2021.

“Actual CO2 output are increasing, while official figures are falling,” stated a senior researcher involved in the study. “That gap is growing and poses a serious problem. Consequently, PHEVs pollute almost as much as petrol cars.”

Key Factors Behind the Discrepancy

Researchers linked the majority of the gap to overestimates of the “electric driving share” – the ratio of kilometers travelled in electric power compared to overall mileage. The team determined that just 27% of driving was done in EV mode, whereas official estimates suggested over four-fifths.

Even, when operating in EV mode, emission amounts were well above official projections. That happened because EV motors were not strong sufficient to operate alone, leading to engines burning fossil fuels for almost one-third of the distance completed in electric mode.

Policy and Financial Consequences

According to calculations, the lowballing of PHEV emissions allowed several major automaker companies to escape more than €5bn in fines between 2021 and 2023, by artificially simplifying adherence with European Union fleet-average CO₂ standards.

Additionally, drivers of PHEVs could spend approximately €500 extra per year in operating expenses than is assumed under laboratory conditions.

“The strong claims that automakers often promote about their plug-in hybrid vehicles are clearly way off the truth,” commented a transport expert. “Buyers are being duped into thinking that by purchasing a PHEV, they are benefiting the planet and saving money. In reality, PHEVs are little better than regular gas and diesel vehicles in terms of energy consumption, CO₂ emissions, and running costs.”

Policy Debate and Industry Pressure

Hybrid vehicles have lately been brought back into policy debates as automakers have pressed the EU to relax CO₂ standards. A planned ban on sales of new combustion engine vehicles in 2035 has faced heavy lobbying from the automotive sector and opposition from member states with significant car manufacturing.

Some high-level officials have suggested PHEVs as a potential “compromise” solution to include in the regulation.

One independent energy economics expert, who was not involved with the study, called the report a “very useful addition” after a long period in which segments of the car industry claimed there was insufficient data to properly evaluate actual CO2 output.

“The results show, without question, that the difference in official and actual PHEV fuel consumption and CO₂ output is much, much greater than for gasoline or conventional cars,” the expert said. “All policy adjustments concerning PHEVs should be implemented with utmost caution and in the light of that evidence.”