Plug-in Hybrid electric Vehicles Emit Almost as Much as Gasoline Cars, Report Finds

Plug-in hybrid cars release nearly 5x more global warming pollution than official figures show, as per a recent report.

Growing Discrepancy Between Official and Real-World CO2 Output

Data reveals that PHEVs emit only 19% less CO₂ than traditional gas and diesel vehicles, based on research conducted by a non-profit group. This differs significantly with laboratory tests, which suggested a three-quarters decrease in pollution.

Analysts studied information from onboard fuel consumption meters of 800,000 vehicles sold in the EU between 2021 and 2023. They discovered that real-world CO₂ emissions from PHEVs in 2023 were 4.9 times higher than lab estimates, up from three and a half times in 2021.

“Actual CO2 output are increasing, while official emissions are decreasing,” stated a senior analyst involved in the report. “This discrepancy is widening and creates a serious issue. As a result, PHEVs pollute nearly as much as petrol vehicles.”

Primary Reasons Driving the Emissions Gap

Analysts attributed the majority of the gap to inflated estimates of the “electric driving share” – the ratio of kilometers travelled in battery power relative to total mileage. The team found that just a quarter of travel was done in electric mode, while lab estimates assumed 84%.

Even, when operating in electric mode, emission levels were well above official projections. That occurred because EV motors were not strong sufficient to operate independently, leading to combustion motors using fossil fuels for almost one-third of the distance covered in EV mode.

Regulatory and Financial Implications

According to calculations, the underestimation of PHEV emissions allowed several large carmaker groups to avoid more than €5bn in penalties between 2021 and 2023, by falsely easing compliance with European Union average fleet CO₂ standards.

Furthermore, owners of PHEVs could pay about €500 more per year in running costs than is assumed under lab tests.

“The strong statements that automakers often promote about their PHEV vehicles are clearly far from the mark,” stated a automotive analyst. “Consumers are being duped into thinking that by purchasing a PHEV, they are helping the planet and cutting money. In reality, PHEVs are only slightly improved than standard gas and diesel cars in terms of energy consumption, CO₂ production, and operating costs.”

Policy Debate and Automotive Lobbying

Plug-in hybrid vehicles have recently been brought again into political debates as automakers have lobbied the EU to weaken CO₂ targets. A proposed ban on sales of new combustion engine cars in 2035 has faced heavy lobbying from the automotive sector and resistance from EU countries with significant car industries.

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

An independent energy economics expert, who was not involved with the study, called the report a “highly valuable addition” after a long period in which parts of the automotive industry claimed there was insufficient data to properly assess real-world emissions.

“The results demonstrate, without question, that the difference between lab and actual PHEV fuel consumption and CO₂ emissions is significantly larger than for petrol or diesel cars,” the expert said. “All policy changes regarding PHEVs should be implemented with utmost caution and considering that evidence.”