Plug-in hybrids (PHEVs), hybrid electric vehicles you can plug in, are almost as polluting as gasoline cars, according to a study by Transport & Environment (T&E), a European umbrella organisation that advocates for sustainable transport.
Car manufacturers are pressuring EU lawmakers to treat hybrid cars as clean vehicles as part of a 'technology-neutral' approach to decarbonising cars, but T&E's analysis of emissions data from 127,000 PHEVs shows they emit far more than claimed – and that the extra fuel consumption costs the average motorist €500 per year.
"The European automotive industry wants plug-in hybrids to be considered carbon neutral, but data from thousands of vehicles shows that PHEVs emit only 19% less CO2 per kilometre on average than gasoline and diesel cars," said T&E.
A PHEV is said to have lower fuel consumption and emissions due to its plug-in battery. In practice, however, the CO2 emissions of plug-in hybrids are almost five times higher than official tests suggest.
Real-world data
"The real-world data deviates significantly from the official 'WLTP' tests (Worldwide Harmonised Light Vehicles Test Procedure, a global driving cycle standard for determining the levels of pollutants and CO₂ emission standards), which involve driving vehicles in a way that regulators consider normal," it said.
In practice, according to T&E, plug-in hybrids emit an average of 135 grams of CO2 per km, compared to an average of 166 grams of CO2 per km for petrol and diesel cars.
Even in electric mode, PHEVs consume an average of 3 litres of petrol per 100 km and emit 68 grams of CO2 per km – 8.5 times more than claimed in official tests, said T&E.
"This is because the electric motors in PHEVs generally lack sufficient power for higher speeds or steep hills, requiring the combustion engine to step in," they said. "According to the data, the engine provides power for an average of almost a third of the distance travelled in electric mode."
