Mercedes team boss Toto Wolff is not expecting another season of utter domination in 2015.
The German team destroyed its rivals in 2014 with 16 victories at the dawn of the new turbo V6 rules, but Wolff said resting on those laurels in a world like Formula One will "quickly catch you out on the wrong foot".
"Especially our records of 2014 will be hard to beat," Wolff told Germany's Sport Bild. "Winning 16 races out of 19 is not normal.
"To want to repeat that would be presumptuous," he added.
Wolff does expect, however, that Mercedes' closest challengers this year will be the same, namely Red Bull and Williams.
Fresh air for Ferrari/Vettel
"When you sign a four-time world champion who is fully motivated, you cannot underestimate how that brings a team forwards," Wolff said.
Similarly, he said Sebastian Vettel's switch means that 2010-2013 world champions "Red Bull will miss him.
"He (Vettel) has gained incredible experience with Red Bull and as a driver, despite the critics, for me he is one of the best," Wolff insisted.
"Ricciardo has shown that he can fill those large shoes and Kvyat is a great talent, but still you have to give them some time."