Plug-in Hybrid Vehicles Pollute Almost as Heavily as Petrol Vehicles, Report Reveals

Plug-in hybrid cars emit nearly five times greater global warming pollution than lab-reported figures show, according to a recent analysis.

Widening Discrepancy In Lab and Actual Emissions

Data reveals that PHEVs release just one-fifth lower CO₂ than conventional gas and diesel vehicles, according to research conducted by a non-profit organization. This contrasts sharply with lab estimates, which suggested a three-quarters reduction in pollution.

Analysts examined information from in-vehicle fuel consumption monitors of 800,000 vehicles sold in Europe between 2021 and 2023. The team discovered that actual CO₂ emissions from PHEVs in 2023 were 4.9 times higher than lab estimates, up from 3.5 times in 2021.

“Real-world emissions are rising, while official figures are falling,” said a lead researcher involved in the report. “That discrepancy is widening and poses a serious problem. As a result, PHEVs emit nearly as much as gasoline cars.”

Primary Factors Behind the Emissions Gap

Analysts linked the majority of the difference to overestimates of the “utility factor” – the ratio of kilometers driven in electric mode relative to overall mileage. They determined that just 27% of driving was done in EV mode, while lab assumptions assumed over four-fifths.

Even, when operating in EV mode, emission amounts were well above official estimates. This occurred because EV motors were not strong enough to function independently, leading to combustion motors burning gasoline for nearly a third of the distance completed in EV mode.

Policy and Financial Implications

According to calculations, the lowballing of PHEV CO2 output enabled several major carmaker companies to avoid more than €5bn in penalties from 2021 and 2023, by falsely easing compliance with EU fleet-average CO₂ standards.

Furthermore, drivers of PHEVs would pay approximately €500 extra annually in running expenses than would be estimated under laboratory tests.

“The strong claims that manufacturers like to make about their plug-in hybrid vehicles are clearly way off the mark,” commented a automotive analyst. “Consumers are being duped into thinking that by purchasing a PHEV, they are helping the environment and saving money. Actually, PHEVs are little better than regular petrol and diesel vehicles in terms of fuel consumption, CO₂ emissions, and running costs.”

Political Discussion and Industry Pressure

Hybrid cars have lately been drawn again into political debates as automakers have lobbied the European Union to relax CO₂ targets. A proposed ban on sales of new internal combustion cars in 2035 has faced heavy pressure from the automotive industry and opposition from member states with significant automotive manufacturing.

Some high-level officials have suggested PHEVs as a possible “flexibility” solution to include in the regulation.

One external energy policy specialist, who was not involved with the study, called the analysis a “very useful contribution” after years in which segments of the car sector argued there was too little data to accurately evaluate real-world CO2 output.

“These findings demonstrate, without question, that the gap between official and real-world PHEV energy use and CO₂ emissions is significantly larger than for gasoline or conventional vehicles,” they stated. “All policy adjustments regarding PHEVs should be made with utmost caution and considering this data.”