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PHEVs produce nearly 5x more planet-heating pollution than lab-reported data indicate, as per a new report.

Widening Gap Between Lab and Actual CO2 Output

Statistics shows that PHEVs release only 19% lower CO₂ than traditional gas and diesel vehicles, based on analysis conducted by a advocacy organization. This contrasts significantly with lab tests, which assumed a 75% reduction in emissions.

Analysts studied information from onboard energy use monitors of eight hundred thousand vehicles sold in the EU between 2021 and 2023. The team found that real-world CO₂ output from PHEVs in 2023 were 4.9 times higher than lab figures, up from 3.5 times in 2021.

“Real-world emissions are rising, while lab-reported figures are falling,” said a senior researcher participating in the study. “This gap is growing and poses a significant issue. As a result, PHEVs pollute nearly as much as petrol cars.”

Primary Reasons Driving the Emissions Gap

Analysts linked the majority of the gap to inflated estimates of the “utility factor” – the ratio of miles travelled in electric power compared to overall distance. The team found that only 27% of travel was done in EV mode, while lab assumptions assumed 84%.

Even, when operating in electric mode, pollution levels were well above lab estimates. That happened because electric motors were not strong enough to operate alone, resulting to combustion motors using fossil fuels for almost a third of the travel covered in EV mode.

Policy and Economic Consequences

According to calculations, the lowballing of PHEV CO2 output enabled several major automaker groups to avoid more than €5bn in fines between 2021 and 2023, by artificially easing adherence with EU fleet-average CO₂ standards.

Furthermore, owners of PHEVs could pay approximately €500 more annually in operating costs than is estimated under laboratory tests.

“The bold statements that automakers like to make about their PHEV cars are clearly far from the truth,” commented a automotive expert. “Buyers are being duped into believing that by buying a PHEV, they are helping the environment and cutting costs. In reality, PHEVs are little better than standard petrol and diesel vehicles in terms of fuel use, CO₂ production, and running costs.”

Political Discussion and Industry Pressure

Hybrid cars have lately been brought again into policy discussions as automakers have lobbied the European Union to weaken CO₂ targets. A proposed prohibition on new internal combustion cars in 2035 has faced intense pressure from the car industry and resistance from EU countries with significant car industries.

Several senior politicians have suggested plug-in hybrids as a possible “flexibility” solution to include in the regulation.

One external energy policy specialist, who was unaffiliated with the study, described the analysis a “very useful contribution” after a long period in which segments of the automotive sector argued there was insufficient data to properly evaluate real-world CO2 output.

“These findings show, without question, that the difference between lab and actual PHEV fuel consumption and CO₂ emissions is significantly greater than for petrol or diesel vehicles,” they stated. “All policy changes regarding PHEVs should be made with utmost care and considering that evidence.”