🔗 Share this article

Plug-in hybrid cars emit almost five times more global warming emissions than lab-reported data indicate, according to a recent report.

Growing Gap Between Official and Actual Emissions

Statistics shows that PHEVs release just 19% lower CO₂ than traditional petrol and diesel vehicles, based on research carried out by a non-profit group. This contrasts significantly with lab estimates, which assumed a three-quarters reduction in emissions.

Analysts examined data from onboard fuel consumption meters of eight hundred thousand cars sold in Europe from 2021 and 2023. The team found that real-world CO₂ output from PHEVs in 2023 were nearly five times greater than lab estimates, up from 3.5 times in 2021.

“Actual CO2 output are increasing, while official emissions are decreasing,” stated a lead researcher participating in the study. “That discrepancy is widening and poses a significant problem. As a result, PHEVs pollute almost as much as gasoline cars.”

Primary Factors Driving the Emissions Gap

Analysts linked the majority of the gap to overestimates of the “electric driving share” – the ratio of miles driven in electric mode relative to total distance. The team found that just 27% of driving was done in electric mode, while lab estimates suggested 84%.

Additionally, when operating in EV mode, pollution amounts were significantly higher than lab projections. This happened because electric motors were not strong enough to operate alone, leading to engines burning fossil fuels for nearly one-third of the distance covered in EV mode.

Regulatory and Economic Consequences

Based on calculations, the lowballing of PHEV emissions enabled four major automaker companies to avoid more than €5bn in fines from 2021 and 2023, by artificially easing adherence with EU average fleet CO₂ standards.

Additionally, owners of PHEVs would spend about €500 more per year in running 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,” stated a automotive expert. “Buyers are being duped into believing that by buying a PHEV, they are helping the planet and saving costs. In reality, PHEVs are little improved than regular gas and diesel cars in terms of fuel use, CO₂ production, and operating expenses.”

Policy Debate and Automotive Lobbying

Hybrid cars have recently been brought back into political discussions as automakers have pressed the European Union to relax CO₂ targets. A proposed prohibition on sales of new combustion engine cars in 2035 has faced heavy lobbying from the car sector and resistance from EU countries with large automotive industries.

Several high-level politicians have suggested plug-in hybrids as a potential “compromise” option to include in the regulation.

One independent energy policy expert, who was unaffiliated with the study, called the analysis a “very useful addition” after a long period in which parts of the automotive sector claimed there was too little information to accurately evaluate actual emissions.

“The results show, without question, that the gap between official and real-world PHEV fuel consumption and CO₂ output is significantly larger than for gasoline or diesel vehicles,” the expert stated. “Any policy adjustments regarding PHEVs should be implemented with extreme caution and in the light of that evidence.”