Britain's advertising regulator has ruled that BMW and MG Motors could not claim that their electric vehicles are "zero emissions" because of the environmental impact of their manufacturing and power generation.
"We understood that when electric vehicles were driven no emissions were produced," the Advertising Standards Authority wrote about a Google ad for BMW seen in August 2023.
"However, in other circumstances, such as the manufacture or charging of an electric vehicle using electricity from the national grid, emissions were generated," ASA said.
The German manufacturer said the "zero emission cars" label was inserted because of Google's automatic keyword feature.
"We welcomed BMW's assurance that the claim would not be repeated in the future," ASA said.
A second decision followed an advert for Chinese-owned British carmaker MG Motor, also seen on Google last August, that claimed its models were "zero emissions".
"The ad made the claim 'zero emissions' without material information that was required to allow consumers to understand on what it was based," ASA said. "The ad must not appear again in its current form."
Colin Walker, head of transport at the Energy and Climate Intelligence Unit, called the decisions "very strange" given the government's efforts to promote electric cars.
"It is accepted practice that cars of all fuel types are assessed by the CO2 they emit from their exhaust pipes," he said.
"It seems perverse that car manufacturers, in an effort to meet the targets they have been set under this mandate for the number of zero emission vehicles that they have to sell, are being told that they can’t market those vehicles as zero emission," he said.