🔗 Share this article

PHEVs release nearly five times more global warming pollution than lab-reported figures indicate, as per a recent report.

Widening Discrepancy Between Official and Actual CO2 Output

Data shows that PHEVs release only 19% less CO₂ than traditional gas and diesel vehicles, according to analysis conducted by a non-profit organization. This differs significantly with laboratory estimates, which assumed a three-quarters reduction in emissions.

Researchers examined data from in-vehicle energy use monitors of eight hundred thousand vehicles registered in Europe from 2021 and 2023. The team discovered that actual CO₂ emissions from PHEVs in 2023 were nearly five times higher than official estimates, up from 3.5 times in 2021.

“Real-world emissions are increasing, while lab-reported figures are falling,” stated a senior analyst participating in the report. “That discrepancy is widening and creates a significant problem. Consequently, PHEVs emit almost as much as gasoline cars.”

Key Factors Driving the Emissions Gap

Analysts attributed the majority of the gap to inflated estimates of the “utility factor” – the ratio of kilometers travelled in electric mode compared to total distance. The team found that just a quarter of travel was done in EV mode, while lab estimates suggested over four-fifths.

Even, when running in electric mode, pollution amounts were well above official estimates. That happened because electric motors were insufficiently powerful sufficient to operate alone, leading to combustion motors using gasoline for nearly a third of the distance covered in electric mode.

Policy and Economic Consequences

According to calculations, the underestimation of PHEV CO2 output enabled four large automaker groups to escape more than €5bn in penalties from 2021 and 2023, by falsely simplifying compliance with European Union average fleet CO₂ standards.

Furthermore, owners of PHEVs would pay about €500 more annually in running costs than would be estimated under lab tests.

“The strong statements that automakers often promote about their plug-in hybrid cars are obviously far from the truth,” commented a automotive expert. “Buyers are being misled into thinking that by buying a PHEV, they are benefiting the environment and saving money. Actually, PHEVs are only slightly better than regular gas and diesel cars in terms of fuel consumption, CO₂ production, and running expenses.”

Political Discussion and Industry Lobbying

Plug-in hybrid cars have lately been drawn again into political debates as automakers have lobbied the European Union to relax CO₂ standards. A planned prohibition on new internal combustion vehicles in 2035 has faced heavy lobbying from the automotive industry and opposition from EU countries with large car industries.

Several high-level officials have suggested PHEVs as a potential “compromise” option to include in the legislation.

One external energy policy expert, who was unaffiliated with the research, described the analysis a “very useful addition” after a long period in which parts of the car industry claimed there was insufficient information to accurately assess actual emissions.

“The results show, beyond any doubt, that the gap in lab and real-world PHEV energy use and CO₂ emissions is significantly larger than for petrol or diesel vehicles,” they said. “All policy adjustments concerning PHEVs should be implemented with extreme care and considering that data.”