Felipe Massa is staying cautious about Ferrari's performance at the Monaco Grand Prix despite a promising start to the weekend on Thursday. The Italian squad, enduring a poor season so far, introduced major upgrades in the previous race in Barcelona, and Massa ran strongly until he had fuel-related issues. The Brazilian, however, admitted he wasn't sure if the team was carrying its momentum. "It's hard to say if there's been an improvement since Barcelona, but we are in amongst the other front-runners, which is already a good sign," said Massa after posting the fifth fastest time in the afternoon session. "Everything went well from the start of the day, when we worked towards the race. From what we've seen today, our car seems to be quick and consistent in performance terms. In the past, I wasn't particularly keen on this track, but more recently that has changed. "Last year, I took pole and today I immediately felt comfortable, working on settings for the car, which we had never tried before. The softer tyres are definitely quicker, but after ten laps or so, you start to lose the back end a bit. "However, we must bear in mind that the track conditions change a lot from today to Saturday, so today's results are not that representative," added the Brazilian, chasing his second points finish of the season following his sixth place at the Spanish Grand Prix. Ferrari team-mate Kimi Raikkonen wound up eighth today, the former champion happy with his day's work. "We worked our way through the usual programme for the first day of practice, based on evaluating the two different types of tyre that Bridgestone has brought here and on finding the best set up on the car," said the Finn. "I would say the car is handling reasonably well: there are still a few areas where we can improve but I am pleased with what we achieved today. "Driving here is always a challenge, even if Sunday's race can then be rather boring, with overtaking practically impossible and if you end up behind slower cars there is nothing you can do but wait for the pit stop."