BERLIN -- The European Union plans to toughen its method for measuring carbon dioxide emissions from plug-in hybrids, two sources familiar with the matter said, after criticism that current tests yield results up to four times below real-world emissions.
The new methodology could mean that some automakers who sold almost as many plug-in hybrids as full-electric vehicles in Europe last year would need to sell more EVs in order to meet EU emissions targets and avoid sizeable fines.
The revised test is likely to be enforced from around 2025, the sources said.
Data from fuel consumption meters -- which under EU law must be built into new cars from 2021 -- will be incorporated into the test, they said. This will show a more realistic picture of how much plug-in hybrids still rely on their internal combustion engine over the electric battery.
"The utility factor will be changed," Petr Dolejsi, sustainable transport director of the lobbying group ACEA told Reuters, referring to the average estimate of how far a hybrid drives in electric-only mode.
"We are starting to collect the data from the vehicles...it is an ongoing process."
A European Commission official said that an amendment to the WLTP test protocol to determine utility factors based on real-life data from fuel consumption meters was under discussion, but that they were not in a position to give further details.
The amendment would next be discussed by the Motor Vehicle Working Group, consisting of stakeholders from industry, the government and consumer associations, on Feb. 9, the official said, with a decision expected this year.
Changing the test to better reflect real-world emissions backs a growing consensus among environmental groups and regulators that plug-in hybrids are not as green as once thought and should not be treated equally to battery-electric vehicles when designing policy to encourage electrification.