Plug in Hybrid Cars Emit Nearly as Heavily as Gasoline Vehicles, Report Reveals

PHEVs emit nearly five times greater planet-heating pollution than official figures indicate, as per a new analysis.

Widening Discrepancy In Lab and Actual CO2 Output

Data reveals that PHEVs release just one-fifth lower CO₂ than traditional petrol and diesel vehicles, according to research carried out by a non-profit group. This differs significantly with lab estimates, which suggested a 75% decrease in emissions.

Analysts studied information from onboard fuel consumption monitors of eight hundred thousand vehicles sold in the EU from 2021 and 2023. They discovered that actual CO₂ output from PHEVs in 2023 were nearly five times greater than lab figures, increased from 3.5 times in 2021.

“Actual emissions are rising, while lab-reported emissions are decreasing,” stated a senior researcher participating in the study. “This gap is growing and creates a significant problem. Consequently, PHEVs emit almost as much as petrol vehicles.”

Key Reasons Driving the Emissions Gap

Researchers linked most of the gap to inflated estimates of the “electric driving share” – the percentage of kilometers driven in battery power compared to total distance. The team found that only 27% of driving was done in electric mode, while official estimates assumed 84%.

Even, when operating in electric mode, emission amounts were well above official estimates. This occurred because electric motors were not strong sufficient to function independently, resulting to combustion motors using gasoline for nearly one-third of the travel completed in electric mode.

Policy and Economic Consequences

Based on estimates, the lowballing of PHEV emissions allowed four large automaker companies to avoid more than €5bn in penalties between 2021 and 2023, by artificially easing compliance with European Union fleet-average CO₂ targets.

Furthermore, drivers of PHEVs could pay about €500 extra per year in operating costs than is estimated under laboratory tests.

“The bold statements that manufacturers like to make about their plug-in hybrid cars are obviously way off the mark,” commented a transport analyst. “Consumers are being duped into believing that by purchasing a PHEV, they are helping the planet and cutting costs. In reality, PHEVs are little improved than standard petrol and diesel vehicles in terms of fuel consumption, CO₂ emissions, and operating costs.”

Policy Debate and Automotive Lobbying

Hybrid vehicles have recently been drawn back into political debates as automakers have pressed the European Union to relax CO₂ standards. A planned prohibition on new internal combustion vehicles in 2035 has faced heavy pressure from the automotive sector and resistance from EU countries with large automotive industries.

Several senior politicians have suggested plug-in hybrids as a possible “flexibility” option to introduce in the legislation.

One external energy policy specialist, who was not involved with the research, called the report a “very useful addition” after years in which parts of the car industry claimed there was insufficient data to properly evaluate real-world CO2 output.

“These findings demonstrate, without question, that the gap between lab and actual PHEV fuel consumption and CO₂ emissions is significantly greater than for gasoline or diesel cars,” the expert stated. “Any regulatory adjustments concerning PHEVs should be made with extreme care and in the light of this data.”