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

Plug-in hybrid cars produce nearly five times more planet-heating emissions than official figures show, according to a recent report.

Growing Discrepancy In Lab and Actual Emissions

Data reveals that PHEVs release only one-fifth lower CO₂ than conventional gas and diesel cars, based on analysis carried out by a advocacy organization. That differs significantly with laboratory estimates, which assumed a 75% decrease in emissions.

Researchers examined information from in-vehicle energy use meters of 800,000 cars registered in the EU from 2021 and 2023. They discovered that real-world CO₂ emissions from PHEVs in 2023 were nearly five times greater than official estimates, up from 3.5 times in 2021.

“Actual CO2 output are increasing, while lab-reported emissions are falling,” said a senior analyst participating in the report. “That gap is widening and creates a significant issue. As a result, PHEVs pollute almost as much as petrol cars.”

Primary Factors Behind the Emissions Gap

Researchers linked the majority of the difference to overestimates of the “electric driving share” – the ratio of kilometers travelled in electric power compared to overall distance. They determined that only 27% of travel was completed in EV mode, whereas official assumptions assumed 84%.

Additionally, when running in EV mode, emission amounts were significantly higher than official projections. This occurred because EV motors were not strong sufficient to function independently, resulting to engines burning gasoline for nearly a third of the travel completed in EV mode.

Regulatory and Economic Consequences

Based on calculations, the underestimation of PHEV CO2 output enabled four large carmaker companies to avoid more than €5bn in fines between 2021 and 2023, by artificially simplifying adherence with European Union average fleet CO₂ standards.

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

“The bold statements that automakers like to make about their plug-in hybrid cars are clearly way off the mark,” commented a automotive analyst. “Consumers are being misled into thinking that by purchasing a PHEV, they are helping the planet and cutting costs. In reality, PHEVs are only slightly better than regular gas and diesel cars in terms of fuel consumption, CO₂ production, and running expenses.”

Policy Discussion and Automotive Pressure

Hybrid cars have recently been brought back into political debates as carmakers have pressed the EU to weaken CO₂ standards. A proposed ban on new combustion engine cars in 2035 has faced heavy lobbying from the car industry and resistance from member states with large automotive industries.

Some senior officials have proposed plug-in hybrids as a potential “compromise” option to introduce in the legislation.

One external energy economics specialist, who was not involved with the study, described the analysis a “very useful addition” after years in which parts of the car industry claimed there was insufficient data to accurately evaluate real-world emissions.

“These findings demonstrate, without question, that the difference between official and actual PHEV energy use and CO₂ output is significantly greater than for gasoline or conventional cars,” they stated. “Any policy adjustments concerning PHEVs should be made with extreme caution and considering this data.”