Ahead of this morning's free practice session, the air temperature is 19 degrees C, while the track temperature is 23 degrees. It is a little cloudier than yesterday.

Nico Rosberg and Kazuki Nakajima dominated the timesheets yesterday fro Williams, with championship leader Jenson Button fourth quickest. However, other than a late charge by BMW in the opening session it is unclear whether some of the teams have made as big a step forward this week as hoped. McLaren appear to have lost ground to Red Bull, Toyota and Brawn while many feel that Ferrari is sandbagging.

The lights go green and Jarno Trulli leads the queue of cars eager to get to work. The tyre options this weekend are hard and soft, however, yesterday there was little discernable difference between the two. That said, some of the teams did little running on the softs, appearing determined to save them for the remainder of the weekend.

Five minutes into the session, everyone has been out for the obligatory installation lap.

Eight minutes into the session, Glock is the first driver to come out for a second run. The German posts the first time of the day, crossing the line at 25.987. Next time around he improves to 24.937.

As Glock raises the benchmark with a 24.640, he is joined by a number of other drivers, including teammate Trulli who immediately posts a 24.512.

BMW go first and second, with Heidfeld posting 23.712 and Kubica 23.741. Alonso goes third, ahead of the Toyotas.

The crowd shows its approval as Alonso goes quickest with a 23.261. Meanwhile, on his first flying lap, Raikkonen goes fourth with a 24.004. Kubica leapfrogs his BMW teammate to go second.

Massa goes quickest in the first two sectors, finally crossing the line at 22.701 to go quickest, as teammate Raikkonen goes second with a 22.902. Vettel goes fourth.

A 23.704 sees Button go seventh, while Hamilton can only manage a 26.449.

Vettel goes third with a 22.999 as Massa raises the benchmark with a 22.638. Elsewhere, Hamilton improves to seventh, crossing the line at 23.476. Fisichella spins but is able to continue.

Buemi goes second with a 22.787, but both Ferraris improve consolidating their places at the top of the timesheets. All but Kovalainen have posted times.

Barrichello goes fourth and Hamilton sixth, as Kovalainen finally makes it on to the timesheets, the Finn going twentieth, 2.411s off Massa's pace. Next time around the Finn improves to seventeenth with a 24.131.

It's all over for Heidfeld who goes off at Turn 12 and hits the ING advertising hoarding. The German gets out of his car and makes his way back to his garage. The car is only damaged at the front, with the left-front wheel hanging from the safety ties. The BMW crew will have a lot of work to do in the next couple of hours.

Just after half-time, it's: Massa, Raikkonen, Buemi, Barrichello, Vettel, Hamilton, Webber, Bourdais, Alonso and Nakajima.

Going quickest in the final sector is enough for the Brazilian to take second overall, while teammate Button remains down in fourteenth. Next time around the Brawn GP driver goes quickest with a 21.906 as Raikkonen spins just after going quickest in the first sector.

Ass Raikkonen goes second with a 21.928, Hamilton leaves the pits, the first driver to use the soft tyres in this session. Elsewhere, Massa goes quickest (21.547) having gone quickest in the final two sectors.

A 22.273 sees Bourdais go fifth, just ahead of his Toro Rosso teammate. Massa improves with a 21.510.

Hamilton goes second with a 21.680, as Bourdais goes quickest in the first sector.

Form out of nowhere, Glock (softs) produces a 1.419 to go quickest, as Button (hard) goes third. Rosberg takes to the escape road the German unable to keep his car on the black stuff and kicking up clouds of dust.

Glock improves with a 21.377, as Button takes second. Trulli improves to sixteenth, as Kovalainen remains twentieth. However, the Finn is back on track on softs, and improves to twelfth with a 22.265. Next time around, he posts 21.896 to go seventh, ultimately going fourth with a 21.519.