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PHEVs emit nearly 5x more planet-heating pollution than lab-reported figures show, as per a recent report.

Growing Discrepancy In Official and Actual Emissions

Statistics reveals that PHEVs emit only 19% less CO₂ than traditional petrol and diesel vehicles, based on research carried out by a non-profit organization. This contrasts significantly with lab tests, which assumed a three-quarters decrease in emissions.

Analysts studied information from onboard energy use meters of 800,000 cars registered in Europe between 2021 and 2023. The team discovered that actual CO₂ output from PHEVs in 2023 were 4.9 times higher than official figures, up from 3.5 times in 2021.

“Actual CO2 output are rising, while official emissions are decreasing,” stated a lead researcher involved in the report. “That gap is widening and poses a significant problem. Consequently, PHEVs pollute almost as much as gasoline vehicles.”

Key Factors Driving the Emissions Gap

Analysts linked most of the gap to overestimates of the “utility factor” – the percentage of miles travelled in electric power compared to total mileage. They determined that only 27% of driving was completed in EV mode, while official assumptions assumed over four-fifths.

Even, when operating in electric mode, emission amounts were well above lab estimates. That occurred because EV motors were not strong sufficient to function independently, resulting to engines using fossil fuels for almost one-third of the travel completed in EV mode.

Regulatory and Economic Implications

Based on calculations, the underestimation of PHEV CO2 output allowed several large automaker groups to avoid more than €5bn in fines between 2021 and 2023, by falsely simplifying compliance with EU fleet-average CO₂ standards.

Furthermore, drivers of PHEVs could spend about €500 extra per year in running expenses than would be estimated under laboratory tests.

“The bold claims that automakers often promote about their plug-in hybrid cars are clearly far from the truth,” commented a transport analyst. “Consumers are being duped into thinking that by buying a PHEV, they are helping the planet and saving costs. Actually, PHEVs are only slightly improved than regular gas and diesel cars in terms of fuel use, CO₂ production, and running costs.”

Policy Debate and Industry Lobbying

Plug-in hybrid vehicles have lately been brought back into policy debates as automakers have pressed the EU to relax CO₂ targets. A planned prohibition on sales of new internal combustion cars in 2035 has faced heavy lobbying from the automotive sector and resistance from EU countries with large automotive industries.

Some high-level politicians have proposed plug-in hybrids as a possible “compromise” option to introduce in the legislation.

One external energy economics specialist, who was unaffiliated with the study, called the report a “very useful addition” after years in which parts of the automotive sector claimed there was too little data to accurately evaluate actual emissions.

“The results show, beyond any doubt, that the difference in official and real-world PHEV energy use and CO₂ output is significantly greater than for petrol or conventional vehicles,” they said. “Any regulatory adjustments concerning PHEVs should be implemented with extreme caution and in the light of this data.”