Nico Rosberg has joined Lewis Hamilton in downplaying Mercedes' pace as the duo topped the times on the final two days of pre-season testing.
Hamilton was quickest on Saturday at the Circuit de Catalunya with his1:20.558 over 0.7s up on the day's second best time.
The Brit, though, immediately downplayed his pace on the soft Pirellis, saying "there is no reason to be impressed."
Handing the car over to Rosberg for the final day of testing, Mercedes remained in the P1 slot as he went even faster than his new team-mate.
The German driver posted a 1:20.130 on Sunday to edge Ferrari's Fernando Alonso by 0.364s.
But rather than taking the plaudits, Rosberg reckons he was only on top because Merc's rivals had yet to show their true potential.
"As we all know, you have to be very careful with the results of testing because you just don't know what other people are doing," he said.
"We know for a fact that our competitors haven't showed their potential by far, we know that for sure.
"What I can say is that we have made progress and I'm pleased with the way the winter has gone. Everything has gone to plan and the reliability has been sorted out. But what also needs to be said is that Melbourne will see completely different conditions again as it will be hotter.
"We know for a fact last year that one of our big weaknesses was tyre degradation. We've learnt a lot about that, but how far are we [to solving the issue], we will have to wait and see.
"Pleased is probably the best word [to describe my feeling], but we'll see."