After a day in which Mercedes dominated the timesheets, Nico Rosberg says his team were "surprised" by their advantage over their rivals.
Mercedes were comfortably ahead of the chasing pack in Friday's first practice with Lewis Hamilton's pace-setting time 1.5s up on Sebastian Vettel's time.
And although the Ferrari driver closed the gap in FP2 on the soft tyres, he was still 0.759s down on the British racer.
"Yes, we are surprised," Rosberg said. "We look really quick here at the moment, I am pleased with that."
Rosberg, though, concedes he needs to find some more pace if he hopes to challenge his team-mate for pole position on Saturday.
He finished the qualifying simulation in the afternoon 0.021s off Hamilton's best.
"Lewis has been pretty quick up to now, but it got very close at the end there as we were trying the qualifying run – 2/100ths – so that's okay.
"We are going in the right direction but there's a lot of work to do."
He added: "It's not gone my way up to now but, of course I will try.
"Tomorrow is another shot and it is very close today and for sure there is a good opportunity tomorrow."