Plug in Hybrid Cars Pollute Nearly as Heavily as Petrol Vehicles, Study Finds

PHEVs release nearly five times more planet-heating emissions than official figures show, as per a recent report.

Widening Discrepancy Between Lab and Actual CO2 Output

Data shows that PHEVs release just 19% less CO₂ than traditional gas and diesel vehicles, based on research carried out by a advocacy organization. That contrasts significantly with lab tests, which suggested a three-quarters reduction in emissions.

Analysts studied data from in-vehicle energy use meters of 800,000 cars sold in the EU between 2021 and 2023. The team found that real-world CO₂ emissions from PHEVs in 2023 were 4.9 times greater than official figures, increased from 3.5 times in 2021.

“Actual CO2 output are increasing, while lab-reported figures are decreasing,” stated a senior analyst participating in the report. “That gap is growing and poses a significant problem. As a result, PHEVs emit nearly as heavily as gasoline vehicles.”

Primary Factors Driving the Discrepancy

Analysts attributed the majority of the gap to inflated estimates of the “utility factor” – the ratio of kilometers travelled in battery mode compared to total distance. The team determined that just a quarter of travel was done in electric mode, whereas lab estimates assumed 84%.

Even, when operating in EV mode, pollution levels were significantly higher than lab projections. This occurred because EV motors were not strong sufficient to operate alone, leading to combustion motors burning fossil fuels for nearly one-third of the travel completed in electric mode.

Policy and Economic Consequences

According to estimates, the lowballing of PHEV CO2 output enabled four large automaker companies to avoid over €5bn in fines between 2021 and 2023, by falsely easing adherence with European Union average fleet CO₂ standards.

Additionally, drivers of PHEVs could spend approximately €500 extra annually in operating expenses than would be estimated under laboratory conditions.

“The strong claims that automakers like to make about their PHEV vehicles are clearly far from the mark,” stated a automotive expert. “Buyers are being misled into thinking that by purchasing a PHEV, they are helping the planet and saving costs. In reality, PHEVs are little better than standard petrol and diesel cars in terms of fuel use, CO₂ emissions, and operating costs.”

Policy Discussion and Industry Lobbying

Plug-in hybrid vehicles have recently been brought back into political discussions as automakers have pressed the European Union to weaken CO₂ targets. A planned ban on sales of new internal combustion vehicles in 2035 has faced heavy pressure from the car industry and opposition from EU countries with large car industries.

Some high-level politicians have suggested PHEVs as a possible “compromise” option to introduce in the legislation.

One external energy economics expert, who was not involved with the study, called the report a “highly valuable contribution” after years in which segments of the automotive sector argued there was insufficient data to accurately assess real-world emissions.

“The results demonstrate, without question, that the gap between official and real-world PHEV fuel consumption and CO₂ output is much, much greater than for gasoline or conventional cars,” the expert stated. “Any policy changes regarding PHEVs should be implemented with utmost caution and in the light of that data.”