That is the claim of the German magazine Auto Motor und Sport, having found that the W03 had the strongest 'long run' pace during recent pre-season tests.
The major daily Bild agrees, crowning the Ross Brawn-led team the "Bluff champion!" of the winter.
"The analysis of recent testing in Barcelona shows that Mercedes are even faster than Red Bull," the report exclaimed.
Brawn is quoted by Brazil's Globo: "You always believe it. You want a winning car, and I have not seen anything that tells me that we don't have (now)."
Perhaps even more sensationally, Sauber ranked second in the Auto Motor und Sport analysis of long runs, although last year the Swiss team looked similarly fast in testing.
Red Bull, McLaren and Lotus come next, followed by the struggling Ferrari.
Peter Sauber wrote in Blick newspaper: "It has never been as difficult as it is this year to get a picture of where everybody stands.
"Why? Because the field has never been so close together."