Ahead of today's first free practice session, the air temperature is 19 degrees C, while the track temperature is 20 degrees. It is pretty overcast.

After the numerous engine changes in Malaysia, we are not expecting quite so many this weekend, with Ferrari claiming that it has no previous plan to opt for engine changes to either Michael Schumacher or Felipe Massa's car.

That said, the FIA has revealed that 15 drivers will start this weekend with fresh power-plants, they are: Fernando Alonso, Kimi Raikkonen, Juan Pablo Montoya, Jarno Trulli, Mark Webber, Nico Rosberg, Jenson Button, Christian Klien, Nick Heidfeld, Tiago Monteiro, Christijan Albers, Tonio Liuzzi, Scott Speed, Takuma Sato and Yuji Ide.

Since Sepang, several teams, including Ferrari, McLaren and BMW, have made changes to their wings, after rivals expressed concern at excessive 'flexing'.

When the lights go green, Wurz is first out on track, followed by Doornbos, Jani, Davidson and Kubica. Ide and Massa are the other 'early risers'.

Whereas most of the drivers return to their garages, Davidson stays out, posting the first time of the Melbourne weekend, 1:43.205.

Speed, Winkelhock, Albers, Villeneuve, Raikkonen and Monteiro, all come out for their installation laps, but it is Alexander Wurz who becomes the second driver to post a time, the WilliamsF1 test driver crossing the line at 1:34.560.

Moments later, the Austrian improves with a 1:31.987, while Kubica goes second, ahead of Davidson and Jani.

Moments after posting his first time of the day, Neel Jani has an off moment. The Toro Rosso locks up, jigs one way then the other, then goes off. The Swiss driver is merely a passenger.

Kubica goes quickest with a 1:30.281, as Sato completes his installation lap.

Felipe Massa waits patiently in the Ferrari garage, as Ralf Schumacher completes his first lap of the weekend.

Jacques Villeneuve is on track, as Doornbos goes quickest in the third sector, improving to third quickest (31.082). The 1997 World Champion goes fifth with a 1:34.828.

Slowly, the times begin to tumble, Kubica improves with a 1:29.576, as Doornbos, Davidson and Villeneuve also improve. Elsewhere, Alonso, Fisichella and Trulli are on track.

Villeneuve goes second with a 1:29.768, as Klien completes his first lap of the weekend. However, it's bad news for BMW as Kubica stops in the first sector with what appears to be a mechanical problem.

Davidson posts a 1:29.159 to take the top spot, and immediately begins another very hot lap. As the Englishman posts 1:28.815, Doornbos slips into second with a 1:29.035. Elsewhere, Ide has a major lock up.

David Coulthard is on track in the Red Bull, the Scot taking fifth spot with a 1:31.727.

With just fifteen minutes remaining, only ten drivers have posted times, with Davidson quickest, ahead of Doornbos, Kubica, Coulthard, Villeneuve, Wurz, Sato, Winkelhock, Ide and Jani.

Moments later, Ralf Schumacher goes seventh (30.037) as Montoya comes out to play. Elsewhere, Monteiro goes tenth with a 1:37.118.

Ralf goes third quickest with a 1:29.411, as Scott speed begins his first hot lap of the day. The American finally crosses the line at 1:36.282, to go eleventh. Meanwhile, Massa goes eighth with a 1:31.889.

Heidfeld and Barrichello are on track as Massa attempts to improve but fails. Elsewhere, teammate Michael Schumacher is on track.

Still no sign of Webber, Button, Rosberg or Liuzzi.

Schumacher can only manage eleventh (31.850), as Kimi Raikkonen begins his hot lap.

As Doornbos has a massive lock up, Davidson and Villeneuve go quickest in different sectors. Meanwhile, Raikkonen goes fourth (28.713).

The session ends with Davidson quickest (1:28.259), ahead of Doornbos, Villeneuve, Raikkonen, Massa, Michael, Ralf, Wurz, Kubica and Klien. Only eighteen drivers posted a time.