Daimler CEO Dieter Zetsche has played down expectations ahead of Mercedes' fourth-consecutive season as a works formula one team.
The Brackley based team has made big changes for 2013; swapping Michael Schumacher for Lewis Hamilton, ousting Norbert Haug and installing Niki Lauda and Toto Wolff in upper management.
"It was evident in the last few years that we have had a good engine, maybe the best, and good drivers, but we were not competitive because of the chassis," Zetsche said in an interview with Salzburger Nachrichten newspaper.
"We did not get to the level that is expected of Mercedes, so the team management had to be reinforced," he insisted.
Zetsche sounded happy with Lauda and Wolff, who were recruited not just as bosses but also shareholders of the Brackley based team.
But he warned: "Improvements are of course not immediately visible after the nomination of new people.
"We should not expect any miracles this year.
"With the new engine next year, we will have more of a chance to implement what we want now," said Zetsche.
Nico Rosberg, who has been with Mercedes since the start of the current project in 2010, has sounded very confident this winter and is predicting race wins.
New recruit Hamilton, however, has been much more guarded, and is quoted by Germany's SID news agency after the Barcelona test: "The best part of our car is the engine.
"The weakest part is the downforce.
"Vettel and Alonso say that Mercedes can fight for the title? I don't really see it like that at the moment."