Plug in Hybrid Cars Emit Almost as Much as Petrol Vehicles, Study Reveals

Plug-in hybrid cars emit nearly 5x more planet-heating emissions than official data show, as per a recent report.

Growing Discrepancy Between Official and Actual CO2 Output

Data shows that PHEVs emit only 19% less CO₂ than traditional petrol and diesel cars, according to analysis carried out by a non-profit group. That contrasts significantly with laboratory estimates, which suggested a three-quarters decrease in pollution.

Analysts studied data from onboard energy use monitors of 800,000 vehicles registered in the EU between 2021 and 2023. They discovered that real-world CO₂ output from PHEVs in 2023 were nearly five times greater than official figures, up from three and a half times in 2021.

“Actual emissions are rising, while lab-reported figures are decreasing,” stated a lead researcher involved in the report. “That discrepancy is widening and poses a serious problem. As a result, PHEVs emit nearly as heavily as gasoline vehicles.”

Key Factors Behind the Emissions Gap

Researchers linked the majority of the difference to inflated estimates of the “utility factor” – the ratio of miles driven in electric power compared to overall mileage. They determined that only a quarter of travel was completed in EV mode, while lab estimates suggested 84%.

Even, when operating in electric mode, emission amounts were well above lab projections. That happened because electric motors were insufficiently powerful sufficient to function independently, resulting to engines using gasoline for nearly a third of the distance completed in EV mode.

Policy and Economic Consequences

According to calculations, the lowballing of PHEV emissions enabled several major automaker groups to escape over €5bn in penalties from 2021 and 2023, by falsely easing adherence with European Union average fleet CO₂ standards.

Furthermore, drivers of PHEVs could spend about €500 extra annually in operating costs than is assumed under laboratory conditions.

“The bold claims that automakers often promote about their plug-in hybrid cars are clearly way off the mark,” commented a automotive expert. “Consumers are being duped into thinking that by buying a PHEV, they are benefiting the environment and saving money. Actually, PHEVs are only slightly better than standard gas and diesel vehicles in terms of energy use, CO₂ emissions, and operating expenses.”

Political Debate and Industry Lobbying

Plug-in hybrid cars have lately been brought back into policy discussions as automakers have pressed the European Union to relax CO₂ standards. A planned prohibition on new internal combustion cars in 2035 has faced intense lobbying from the automotive sector and opposition from EU countries with large automotive manufacturing.

Several high-level politicians have proposed PHEVs as a possible “compromise” solution to include in the regulation.

One independent energy economics specialist, who was unaffiliated with the research, called the report a “very useful addition” after a long period in which segments of the car sector argued there was too little data to accurately assess real-world CO2 output.

“The results show, beyond any doubt, that the difference between official and real-world PHEV energy use and CO₂ output is significantly greater than for gasoline or diesel cars,” the expert said. “Any policy changes regarding PHEVs should be implemented with extreme care and in the light of this data.”