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

Plug-in hybrid electric vehicles emit nearly 5x greater planet-heating pollution than official data show, as per a new analysis.

Growing Gap Between Official and Actual Emissions

Statistics reveals that PHEVs emit only one-fifth lower CO₂ than traditional petrol and diesel cars, based on research conducted by a advocacy group. This differs significantly with lab estimates, which assumed a 75% reduction in pollution.

Researchers studied information from in-vehicle energy use meters of 800,000 cars sold in the EU from 2021 and 2023. The team discovered that real-world CO₂ emissions from PHEVs in 2023 were nearly five times higher than lab estimates, up from three and a half times in 2021.

“Actual CO2 output are increasing, while official emissions are falling,” stated a lead researcher participating in the study. “That discrepancy is growing and creates a serious problem. Consequently, PHEVs pollute nearly as much as gasoline cars.”

Primary Reasons Behind the Emissions Gap

Analysts linked the majority of the difference to inflated estimates of the “utility factor” – the percentage of miles driven in electric mode compared to total mileage. They found that only 27% of driving was completed in EV mode, while lab assumptions suggested 84%.

Even, when running in electric mode, pollution levels were well above lab estimates. That occurred because electric motors were insufficiently powerful enough to function independently, resulting to combustion motors using gasoline for almost a third of the travel completed in electric mode.

Policy and Economic Implications

According to calculations, the lowballing of PHEV emissions enabled four large automaker groups to escape over €5bn in penalties between 2021 and 2023, by falsely easing adherence with EU fleet-average CO₂ standards.

Furthermore, owners of PHEVs would pay about €500 more annually in operating expenses than would be estimated under laboratory conditions.

“The strong claims that manufacturers like to make about their plug-in hybrid cars are obviously far from the mark,” stated a transport expert. “Buyers are being duped into thinking that by purchasing a PHEV, they are benefiting the environment and cutting money. In reality, PHEVs are little improved than standard petrol and diesel vehicles in terms of energy use, CO₂ emissions, and running expenses.”

Political Debate and Automotive Lobbying

Plug-in hybrid cars have lately been brought again into political debates as carmakers have lobbied the EU to weaken CO₂ targets. A proposed prohibition on sales of new combustion engine cars in 2035 has faced intense lobbying from the automotive sector and opposition from EU countries with significant car industries.

Several high-level politicians have suggested plug-in hybrids as a potential “flexibility” option to include in the legislation.

An external energy economics expert, who was not involved with the study, called the analysis a “highly valuable addition” after a long period in which segments of the automotive sector claimed there was insufficient information to properly assess real-world CO2 output.

“The results demonstrate, without question, that the gap in lab and real-world PHEV energy use and CO₂ output is much, much larger than for petrol or diesel vehicles,” the expert stated. “Any regulatory changes concerning PHEVs should be made with extreme caution and considering this evidence.”