Christian Horner has played down expectations for Red Bull’s first year with works Honda power.
One of F1’s top three teams, the energy drink owned outfit will start using Japanese-made engines from 2019.
But boss Horner told La Gazzetta dello Sport: "I certainly expect that the first year will be an interim year for us.
"Compared to the competition, the necessary steps still have to be taken at Honda," he added.
But Horner said that Red Bull has not been happy with its season this year, which is the last in a long-term collaboration with Renault.
"We wanted more," he said.
"We could have won in Bahrain and had a double podium in China and Monaco. But we are the only ones who can make life difficult for Ferrari and Mercedes," Horner added.