Kimi Raikkonen is refusing to get carried away with the pace of the Ferrari in pre-season testing.
The Finn has set the fastest time on both his days in the car and the third quickest lap of the week overall.
Asked if the team was optimistic after its strong showing in the first week, Raikkonen said: "You are optimistic every year, but then where it turns out to be at the end of the year is hard to say.
"But we have learned our lessons from the past years and the team has done a good job over the winter. Is it going to be good enough? We will see during the year, but so far it has been a good feeling and we can't complain too much.
"I think this [reliable running] is more or less what you want to do every year and some years go smoothly and others not. This week so far has been good, but there is still another week to go and a lot of work to be done, but we cannot complain too much -- it's been a pretty okay start."
Raikkonen was on the soft tyres for his fastest times on day two and four, but said Ferrari had yet to show its true pace on a qualifying style run.
"I doubt we are going to try to go full out [during testing], but we have to practice some qualifying stuff, but which day we are going to do it, I don't know. Pure lap time doesn't really count, it's just get there, get the job done and we will see in two or three weeks at the first race where we are going to finish."