Ahead of today's second, and final, free practice session, the air temperature is 28 degrees C, while the track temperature is 31 degrees. It remains warm and bright, but with a lot of cloud.

The Toro Rossos are first out, Vettel keen to make up for the time he lost this morning following his engine failure. Glock is also on track, as are the Williams, Red Bulls and Renaults.

Once the dust settles, Piquet tops the timesheets with a 22.183, ahead of Alonso, Rosberg, Nakajima, Bourdais and Vettel.

No sooner has Nick Heidfeld gone third with a 22.644, than Lewis Hamilton raises the benchmark with a 21.436. Meanwhile, further problems for Vettel who pulls off to the side of the track again, this time just eight minutes to the session. It was a hydraulics failure that sidelined him this morning, wonder if it's a repeat of the same problem.

The replay shows that the German slows with a problem, pulls off track but then rejoins, right in front of Timo Glock. The Toyota driver, in his attempt to avoid the Toro Rosso, is almost collected by a Renault and BMW. Luckily, there are no comings together. Nonetheless, it's all over for Vettel.

A 21.351 sees Kovalainen go quickest, the Finn running on softs - as opposed to super-softs. However, moments later his English teammate posts 21.123. Behind the McLarens, the BMWs are third and fourth quickest.

As Kovalainen improves with a 21.024, Raikkonen goes eighth (22.241), and Massa heads down the pitlane.

The World Champion improves to fifth (22.047), while Massa goes fifteenth with his first flying lap. Next time around the Ferrari duo improve to third and ninth.

Kubica complains of graining as Massa goes third, leapfrogging his Ferrari teammate, with a 21.272.

With the big guns having set competitive times, the real work begins, the long runs whereby drivers work on set-up for tomorrow's qualifying session and Sunday's race. Most of the top times, thus far, have been set on the soft option tyre, the super-soft sure to appear in the closing stages of this session.

That said, Hamilton (super-softs) goes quickest in the middle sector, however, a poor final sector sees him fail to improve. Replay shows a beautiful drift from the English driver's McLaren.

Never one to quit, Hamilton continues plugging away, finally posting a 20.891 tore-take the top spot. The McLaren appears to be working well with the super-soft compound.

It was perfect symmetry on the timesheets - McLaren, Ferrari, Toyota and BMW until Kubica improved, thereby splitting Trulli and Glock. Bourdais is ninth, ahead of Alonso, Piquet and Fisichella.

Nakajima and Rosberg are both on track, both running on super-softs. They improver to eighth and ninth, but they won't be up there for long. In all honesty, Williams appears to be falling further and further behind as the season progresses.

Coulthard goes tenth as Kubica complains that his car is getting "worse and worse". The more laps he completes the more his tyres are not working but he's at a loss ti understand why. "I don't know what's happening," he admits, "but it's not good".

With thirty-six minutes remaining, it's: Hamilton, Massa, Kovalainen, Kubica, Raikkonen, Trulli, Glock, Rosberg, Nakajima and Coulthard.

Kovalainen (super-softs) re-takes the top spot with a 20.760, only for Hamilton (softs) only to snatch it back moments later with a 20.600. Elsewhere, Raikkonen gets horribly out of shape but somehow holds it together.

As Rosberg attempts to improve on seventh, Heidfeld complains of graining. He's not alone.

With twenty minutes remaining, Heidfeld has completed the most laps 935), ahead of Webber (32) and Piquet (31), with Kubica, Trulli, Bourdais, Button and Fisichella all on 30.

Hamilton goes for a run on softs, he's not going for an improved time, but he's really pushing, clearly in an attempt to scrub them in. Alonso too is pushing very, very hard. Indeed, the Spaniard (super-softs) improves to third with a 20.928.

Hamilton is fastest through the speed-trap at 296 kph, ahead of Raikkonen, Kovalainen and Bourdais all on 292.

Just under nine minutes remaining, and Kovalainen (softs) goes quickest in the first sector. He sets a personal best in the second, but a poor third sees him fail to improve.