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

Plug-in hybrid cars produce almost 5x more planet-heating emissions than official data show, as per a new analysis.

Growing Discrepancy Between Official and Actual Emissions

Data reveals that PHEVs release only 19% lower CO₂ than traditional gas and diesel vehicles, based on research conducted by a advocacy organization. This contrasts significantly with lab tests, which suggested a three-quarters reduction in pollution.

Analysts studied data from onboard fuel consumption meters of 800,000 vehicles registered in Europe between 2021 and 2023. The team discovered that actual CO₂ output from PHEVs in 2023 were nearly five times greater than lab figures, increased from three and a half times in 2021.

“Real-world emissions are rising, while official emissions are decreasing,” said a senior researcher involved in the report. “This discrepancy is growing and poses a serious issue. Consequently, PHEVs emit nearly as heavily as gasoline vehicles.”

Key Factors Driving the Discrepancy

Analysts linked most of the difference to overestimates of the “utility factor” – the percentage of kilometers travelled in battery mode relative to overall distance. They determined that just 27% of driving was completed in electric mode, whereas lab estimates assumed over four-fifths.

Additionally, when running in EV mode, pollution levels were well above lab projections. This occurred because electric motors were insufficiently powerful enough to operate independently, resulting to engines using fossil fuels for almost one-third of the distance covered in electric mode.

Policy and Financial Consequences

According to estimates, the underestimation of PHEV CO2 output enabled four major automaker companies to avoid more than €5bn in fines between 2021 and 2023, by artificially easing adherence with EU average fleet CO₂ targets.

Additionally, drivers of PHEVs would pay approximately €500 more annually in running expenses than would be estimated under lab conditions.

“The bold statements that manufacturers often promote about their plug-in hybrid cars are clearly far from the truth,” commented a automotive analyst. “Consumers are being misled into thinking that by buying a PHEV, they are benefiting the environment and cutting money. Actually, PHEVs are only slightly better than regular gas and diesel cars in terms of energy use, CO₂ production, and running expenses.”

Policy Debate and Automotive Pressure

Plug-in hybrid vehicles have recently been brought again into political discussions as automakers have pressed the EU to weaken CO₂ standards. A planned prohibition on sales of new internal combustion cars in 2035 has faced heavy pressure from the automotive sector and opposition from EU countries with large automotive industries.

Some high-level officials have suggested PHEVs as a possible “flexibility” option to introduce in the regulation.

An external energy policy expert, who was unaffiliated with the study, called the analysis a “very useful contribution” after a long period in which segments of the automotive industry claimed there was insufficient data to properly assess actual emissions.

“The results demonstrate, without question, that the difference between lab and real-world PHEV fuel consumption and CO₂ output is significantly greater than for petrol or diesel cars,” the expert stated. “Any policy changes regarding PHEVs should be made with extreme care and in the light of this evidence.”