A complaint taken against Shell by a rival fuel company relating to its campaign for a fuel additive was dismissed by the Advertising Standards Board, a court has been told.
Shell is before the Wellington District Court defending 22 charges laid by the Commerce Commission under the Fair Trading Act.
The Shell advertising campaign claimed its Fuel Economy Formula was 'designed to take you further'.
But the Commerce Commission says the ads were misleading, as tests showed using a tank of the fuel only increased the distance travelled by less than 1%.
Shell's lawyer Les Taylor told the court on Tuesday that the commission and all its witnesses acknowledged that the claim made about the fuel was literally true.
Mr Taylor said Shell was the only company to have proven a fuel economy benefit for its additive and was proud of its achievement in developing such a product.
Eric Holthusen, who helped develop the additive, said Shell had not wanted to quantify claims about the product because a range of factors could affect individual vehicles.
He said they include road and weather conditions, and the age and type of vehicle.