On-road carbon emissions from plug-in hybrid cars are about 2.7 times those reported in laboratory tests, environmental groups said on Wednesday, accusing manufacturers of making “false claims.”
Analysis of carbon dioxide emissions data from studies across Europe suggested that plug-in hybrid electric vehicles (PHEVs) produced an average of 117 grams of CO2 per kilometre, compared with just 44 grams in laboratory tests.
The higher emissions figure puts PHEVs much closer to petrol and diesel cars, which emit averages of 164-167 grams of CO2 per kilometre, said Transport & Environment and Greenpeace UK.
Manufacturers’ tests failed to consider factors such as design features requiring the engine to run, a limited electric range, and drivers’ tendency not to charge their cars as often as possible, the groups said.
“Plug-in hybrids are the car industry’s wolf in sheep’s clothing,” said Rebecca Newsom, head of politics for Greenpeace UK.
“They may seem a much more environmentally friendly choice but false claims of lower emissions are a ploy by car manufacturers to go on producing SUVs and petrol and diesel engines,” Newsom said.
Transport & Environment said its data, compiled from sources representing some 20,000 PHEVs in fleets or private use, were “shocking.”
It said manufacturers wrongly marketed plug-in hybrids, which are powered by both a conventional engine and a storage battery, as “zero-emission capable electric cars.”
“Even when a PHEV is driven in the supposed zero-emission mode, most continue to use their engine, burning fuel and emitting CO2,” it said.