New testing commissioned by clean transport group Transport & Environment (T&E) shows that plug-in hybrids (PHEV) emit considerably more CO2 than advertised, and the problem could be even worse as drivers charge up before entering low emissions zones.
The results of testing has led the influential European NGO to label plug-in hybrids as “fake electric cars” designed solely by car makers to pass lab tests and achieve more sales via tax breaks.
The Emissions Analytics research, which included PHEV versions of the BMW X5, Volvo XC60 and Mitsubishi Outlander, found that even when driving on a full battery, emissions were 28-89% higher than advertised by the car makers.
Once the battery is empty, T&E estimates the engines in these vehicles quickly overshoot the stated emissions after 11-23km of driving, resulting in as much as eight times the official emissions ratings determined in WLTP tests.
And the problem becomes worse in cities such as London and Madrid, which have low emissions zones where plug-in electric vehicles are only allowed to drive on electric power.
T&E says that when put in “battery charging mode” to top up a battery before entering these zones, emissions can be up to 12 times that of official numbers.
The tax incentives T&E is referring to include up to a €6,750 grant towards the purchase of new PHEVs in Germany, and a €2,000 incentive in France.
While the purpose of such incentives is to reduce transport-related emissions, they have instead been criticised by European media for instead subsidising the purchase of large plug-in hybrid SUVs such as the BMW X5 PHEV, which are polluting more than the car makers claim.
“Plug-in hybrids are fake electric cars, built for lab tests and tax breaks, not real driving,” Julia Poliscanova, senior director for clean vehicles at T&E, said in a statement.
“Our tests show that even in optimal conditions, with a full battery, the cars pollute more than advertised. Unless you drive them softly, carbon emissions can go off the charts. Governments should stop subsidising these cars with billions in taxpayers’ money.”
She says that while blame for driving inefficiently has been shifted onto drivers, it is car makers’ fault for making PHEVs that are not powerful enough, or with enough useful driving range or charging speed.
In fact, the two premium PHEVs tested by Emissions Analytics – the BMW X5 and Volvo XC60 – cannot fast charge, meaning drivers were less likely to top up the batteries unless they had a few hours to do so.
Additionally, T&E criticise Mitsubishi for designing the Outlander PHEV in such a way that the engine would turn on (as per its own user manual), “if the PHEV system is too hot or too cold, if quick acceleration is applied, or if the air conditioning is operating.”
“Carmakers blame drivers for plug-in hybrids’ high emissions. But the truth is that most PHEVs are just not well made,” said Poliscanova.
“They have weak electric motors, big, polluting engines, and usually can’t fast charge. The only way plug-ins are going to have a future is if we completely overhaul how we reward them in EU car CO2 tests and regulations. Otherwise PHEVs will soon join diesel in the dustbin of history.”
Bridie Schmidt is lead reporter for The Driven, sister site of Renew Economy. She specialises in writing about new technology and has been writing about electric vehicles for two years. She has a keen interest in the role that zero emissions transport has to play in sustainability and is co-organiser of the Northern Rivers Electric Vehicle Forum.