Ahead of today's sole free practice session the air temperature is 31 degrees C, while the track temperature is 35 degrees. As the sun sets, the sky is clear the white clouds tinged with pink and orange.

The bug news is that Rubens Barrichello's is using an old gearbox this morning before the team switches back to his Monza unit this afternoon. This unit, which was the cause of much deliberation in Italy, is the same gearbox that first caused problems in Belgium.

The lights go green and within the first minute or so there are seventeen cars on track with only Raikkonen and the Brawns opting to stay put. That said, the 2007 champion heads down the pitlane.

As the drivers head back to the pits, their installation lap completed, Button and Barrichello leave the Brawn garage.

Eight minutes into the session, Fisichella is the first driver to come out for a second run. As he begins his first flying lap he is joined by Grosjean. Despite a strong first sector, Fisichella loses time behind the Frenchman who is still on his out lap.

Alguersuari grinds to a halt at the end of the pitlane. However, it isn't too long before he is rescued by his mechanics.

Fisichella crosses the line at 58.445 to post the first time of the day. However, moments later Grosjean posts a 52.436.

A 51.794 sees Raikkonen go quickest as Buemi goes quickest in the middle sector. The Swiss driver crosses the line at 52.229 to go second ahead of Rosberg.

Having gone quickest in the first two sectors, Rosberg crosses the line at 50.134, as Sutil goes third ahead of Kubica and Button.

Twenty minutes into the session, Kubica goes quickest with a 49.679, with six drivers still to post a time.

Raikkonen gets it wrong at Turn 18, the Finn being left with nowhere to go other than come to a complete halt and then put the F60 in reverse.

As Kovalainen goes third (49.788), Hamilton goes quickest in the first sector. The Englishman is quickest again the second sector, finally crossing the line at 48.346 to go quickest.

A 49.185 sees Barrichello go second leaving Webber as the only driver yet to post a time.

As Hamilton posts another quick first sector, Heidfeld and Alonso go fourth and fifth.

Bang on the half-hour, from out of nowhere Vettel produces a 49.154 to go second, albeit 0.808s off Hamilton's best.

Webber goes sixteenth with a 51.302, next time around improve with a 50.315 to thirteenth.

At half-time, it's: Hamilton, Vettel, Barrichello, Kovalainen, Heidfeld, Alonso, Kubica, Rosberg, Button and Glock.

Clearly pushing very hard, Vettel has a couple of moments. Elsewhere, Sutil gets up close and very personal with the wall.

No serious running of the option (super-soft) tyre thus far, though that will change as we enter the final stages of the session.

Kovalainen posts 48.427 to go quickest as Glock improves to third with a 48.680, both drivers on the prime tyre.

Having gone quickest in the second sector, Hamilton crosses the line at 48.197 thereby raising the benchmark ever higher. Elsewhere, Liuzzi does a 360.

Rosberg splits the two McLarens with a 48.332 as Trulli goes sixth (48.796). Thirteen minutes remaining.

Raikkonen, currently nineteenth, is one of the first drivers to run the option tyre (super-soft). He improves to seventh with a 48.864.

Vettel posts 47.938 to take the top spot by 0.259. The German, like Raikkonen, is on the option tyre. Next time around the Red Bull driver raises the benchmark with a 47.909.

Rosberg improves to third (48.332) the German and his team appearing to rediscover its pre-Monza pace.

Having gone quickest in the first sector, Hamilton has to use the escape road at Turn 8.