World champion Michael Schumacher set a new lap record on his second day of testing in Ferrari's new car.
The Ferrari will look different by the time of the first race
Schumacher set a lap of 56.279 seconds at Ferrari's Fiorano track on Saturday while doing a race simulation, beating the 56.338secs mark he set last March.
"It was a good debut, with no problems. I'm somewhat happy," Schumacher said.
"However, we must understand the car's efficiency as compared with the other teams. I must say that the new Williams and Renault cars look very strong."
Schumacher witnessed those two cars in testing in Spain last week, but has yet to drive at the same test as McLaren's new model, the machine he has said he most fears.
Schumacher added: "The evolution continues. Every year we are more precise, a little closer to perfection.
"Everyone has done a great job in achieving this step up in
quality and I have no worries at the moment. This car gives us a realistic chance of fighting for the title."
He had said after Friday's first day's running: "I am quite happy with the first test of our new car. I immediately had a feeling for it.
"The F2004 was handling very well straight out of the box and we achieved good and consistent lap times."
Ferrari launched the new car on Monday but team bosses said at the time that some key parts, mainly to do with the aerodynamics, were not finished.
They said the car would look very different when the season starts in Australia on 7 March.
Schumacher, winner of a record sixth title last year, tested the old F2003-GA in Valencia earlier in the week and returned to Italy on Thursday for the new car's first run.
Tests of the new Ferrari are set to continue at the
Mugello circuit, near Florence, next week, a much more exacting test of a car's capabilities than Fiorano.
It is traditional for new Ferrari F1 cars to break the lap record at Fiorano.
Last year's F2003-GA clocked a best lap on its debut last February of 57.045 seconds.