Carbon emissions from plug-in hybrid vehicles (PHEVs) are an average of two-and-a-half times higher than official tests indicate, environmental campaigners have warned.
Greenpeace and the European NGO Transport & Environment claimed their analysis shows a typical PHEV emits 117g of CO2 per kilometre, compared with the 44g suggested in laboratory examinations.
PHEVs run on a battery charged with electricity from the grid or through a conventionally-fuelled engine.
They are marketed as low-carbon alternatives, but environmentalists claim the limited electric range of the vehicles and owners not charging their batteries as often as possible increases their emissions.
The analysis is based on data from a variety of sources and including 20,000 PHEVs driven across Europe.
Reacting to the findings, Tom Spencer editor of consumer advice website IrishEVs.com said hybrid vehicles were being marketed as "electric" to tap into the growing desire for zero-emissions transport, "yet they are almost as harmful as petrol or diesel cars".
He added: “This detracts from efforts to increase the use of battery electric vehicles, which do not emit any harmful pollution and which can be run using renewable energy. As such we support calls to ban the sale of hybrid vehicles in 2030, alongside the impending ban on the sale of new petrol and diesel vehicles.”
The Government has committed to banning the sale of new petrol and diesel vehicles from 2030, whereas the UK government has indicated a ban on sales of new petrol, diesel and hybrid cars and vans could be brought forward from 2040 in a bid to meet its decarbonisation targets.
Greenpeace UK's head of politics Rebecca Newsom said: "Plug-in hybrids are the car industry's wolf in sheep's clothing. 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."
UK director of Transport & Environment Greg Archer, said: "PHEVs are not electric cars and claims that in cities plug-in hybrids have zero emissions are just mischievous, misleading marketing."
Unless the battery was frequently charged, “these fake electric cars are actually worse for the climate than conventional cars,” he believed.
Mike Hawes, chief executive of the Society of Motor Manufacturers and Traders, acknowledged there were difference between lab tests and real-world use of cars. But he accused the pressure groups of analysing figures that "government and industry abandoned two years ago" in favour of a "more robust" test.
He added: “Even the report’s assumed figures show plug-in hybrid vehicles provide more than a 30 per cent overall reduction in emissions compared to petrol or diesel.”
“PHEVs also provide a flexibility few other technologies can yet match with extended range for longer, out of town journeys, and battery power in urban areas, reducing emissions and improving city air quality,” Mr Hawes said.
The range and performance of PHEVs would continue to improve, he predicted, while for many users “they are the essential stepping stone to a fully electric vehicle”.– Additional reporting PA