Plug in Hybrid Cars Pollute Almost as Heavily as Petrol Cars, Report Finds

Plug-in hybrid cars produce nearly 5x more global warming emissions than official data show, as per a new report.

Growing Gap Between Lab and Real-World CO2 Output

Statistics shows that PHEVs emit just one-fifth less CO₂ than traditional gas and diesel vehicles, according to research conducted by a advocacy organization. This differs sharply with lab estimates, which suggested a three-quarters decrease in emissions.

Analysts examined information from onboard energy use monitors of eight hundred thousand cars sold in Europe between 2021 and 2023. They discovered that real-world CO₂ output from PHEVs in 2023 were nearly five times greater than official estimates, up from three and a half times in 2021.

“Real-world emissions are rising, while official figures are decreasing,” said a senior analyst involved in the study. “That gap is widening and creates a significant issue. As a result, PHEVs pollute nearly as much as gasoline vehicles.”

Key Factors Behind the Emissions Gap

Analysts attributed most of the gap to overestimates of the “utility factor” – the ratio of miles driven in electric power compared to total distance. The team determined that only a quarter of driving was done in electric mode, while lab assumptions assumed over four-fifths.

Even, when running in EV mode, emission levels were well above official estimates. That happened because electric motors were insufficiently powerful sufficient to function independently, leading to engines using fossil fuels for almost one-third of the distance completed in EV mode.

Policy and Economic Consequences

Based on estimates, the lowballing of PHEV CO2 output allowed several major carmaker companies to escape over €5bn in penalties from 2021 and 2023, by falsely easing adherence with EU fleet-average CO₂ standards.

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

“The strong statements that automakers like to make about their PHEV cars are clearly far from the truth,” stated a automotive analyst. “Consumers are being misled into thinking that by buying a PHEV, they are helping the planet and cutting money. In reality, PHEVs are little improved than standard gas and diesel cars in terms of fuel use, CO₂ emissions, and running costs.”

Policy Debate and Industry Lobbying

Plug-in hybrid cars have recently been brought again into political debates as automakers have lobbied the European Union to relax CO₂ targets. A planned ban on new internal combustion cars in 2035 has faced heavy pressure from the automotive sector and opposition from EU countries with significant car manufacturing.

Several senior officials have proposed PHEVs as a possible “flexibility” option to include in the regulation.

An external energy economics specialist, who was unaffiliated with the study, described the report a “very useful addition” after years in which parts of the car industry claimed there was too little information to accurately evaluate real-world CO2 output.

“The results demonstrate, without question, that the gap in lab and real-world PHEV fuel consumption and CO₂ output is much, much larger than for gasoline or diesel cars,” the expert said. “All policy changes regarding PHEVs should be implemented with utmost caution and considering that evidence.”