Despite dominating the championship for the last four years, Toto Wolff insists there is no guarantee that Mercedes will secure a fifth double in 2018.
Mercedes have been the team to beat since Formula 1's swap to V6 engines in 2014.
Last year, though, they were at least given a bit of competition by Ferrari who led throughout the first half of the season.
But with Mercedes coming out on top in the development race, and Ferrari imploding after the summer break, it was Mercedes who walked away with both titles.
— Mercedes-AMG F1 (@MercedesAMGF1) February 1, 2018
Wolff, though, isn't betting on a fifth successful double.
"No, because all the points go back to zero," said the motorsport boss.
"We are extremely happy and proud of the four double titles but it isn't a guarantee that we'll get it a fifth time.
"The mindset in the organisation is to stay humble of your own achievements but motivated and energised and hopefully try to win races again in order to fight for the title."
Asked about who he expects to be Mercedes' main rivals this season, he sidestepped the question saying their biggest obstacle could be Pirelli's new hypersoft tyre.
"It is difficult to judge," he said.
"Last year Ferrari surprised all of us as they put a car on the track that was fast from the get-go.
"This year the rules are more stable but there's a tyre that is ocming into the equation so the truth is we don't know."