Kimi Raikkonen was surprised to finish as high as fourth in FP2 after a "messy" opening day to practice for the Malaysian Grand Prix.
Raikkonen finished the session 0.2s behind Ferrari teammate Sebastian Vettel. The pair were significantly down on the Mercedes drivers over one lap, though the long run pace between Mercedes, Ferrari and Red Bull looked much closer.
"Quite a messy day from our side, at least from me," Raikkonen said after FP2. "Not very smooth running. The feeling wasn't very good all day so I'm a bit surprised with the lap time.
"It's not too bad, comparing how the feeling is, and I'm sure we can improve tomorrow, but not an ideal day."
Raikkonen is happy Ferrari has enough time to hone in on the perfect set-up in time for qualifying.
"We have to sit down and look things through and like I said it has been far from smooth running all day, so that didn't help. The feeling wasn't good, but the lap time wasn't disastrous, so I'm sure we can improve."
Vettel won last year's Malaysian Grand Prix as Ferrari -- partly due to how it excelled in the hot conditions. However, Raikkonen has downplayed the importance of a hot weekend this time around.
"I don't know if it's going to make a lot of difference. If you take purely from recent years and races it's probably better for us if it's a bit hot. But I don't think it's going to suddenly change the whole picture."