Sebastian Vettel says he is staying cautious about the pace of Red Bull at Monza, although the German admitted the team has learned the lessons from last year.
The Milton Keynes squad endured a difficult race last season at the Italian track, and has arrived in Monza among doubts about its prospects.
Vettel, however, posted the quickest time of the day in the second practice session.
Despite that, the German believes the real pace of his rivals will be seen tomorrow.
"I wouldn't say surprised," said Vettel. "We learned our lesson last year after we got hammered quite badly here, so I think we did a step forward. But we need to be patient.
"Tomorrow we will see the true pace, McLaren is extremely quick and their cars went off a couple of times so I don't know if they had a clean afternoon.
"Ferrari was quick in the afternoon too - it is a short lap here, a lot of straights, not so many corners so the gap between cars will be very small."
Vettel admitted he was still pleased with his day's work, but conceded it was hard to read into the times.
"I am quite happy. I think it was quite good today. It was a Friday so lap times may vary, you don't know the fuel loads but I am pretty confident - it looks much better here today than it probably did one year ago. Obviously no KERS here this year helps us, and it is looking quite good.
"It is tight. We looked quite good today, Ferrari was very quick this afternoon and McLaren up there all day long and they are deciding the pace, so it will be tight tomorrow."
Team-mate Mark Webber, sixth quickest, was also encouraged by the pace of his car.
"We will see how we go tomorrow. We are in the ballpark which is nice. Ferrari look strong as well," said the Australian.
Webber was forced to stop in the second session because of a problem with his car, but he downplayed the issue.
"They told me turn the car off, water pressure, and that's it. No big drama."