Ahead of today's opening session the air temperature is 27 degrees C, while the track temperature is 35 degrees. It is bright and sunny.

Tyres this weekend are hard (prime) and medium (option). As in 2012 there is one DRS zone and it is on the main pit straight, albeit slightly longer than last year.

Naturally (groan) Red Bull is expected to be very strong here, with Mercedes and Lotus also due a good showing while Ferrari is likely to struggle for grip.

There is one reserve driver on duty this morning, Heikki Kovalainen taking over Charles Pic's car.

The lights go green and Mark Webber is first out, the Australian at the wheel of the chassis he drove in Hungary, his regular car having been damaged in last week's crash. He is joined by Ricciardo, Raikkonen, Bianchi and Maldonado.

Within a couple of minutes all but Hamilton have been out, Ricciardo, Raikkonen, Grosjean, Vergne and Vettel each completing two installation laps.

Finally, Hamilton heads out, the Mercedes driver, like several others, sporting a special helmet for this race.

Seventeen minutes into the session, Maldonado is the first driver out for a second time. The Williams driver known to be very frustrated with the Grove outfit's performance this season and understood to be looking at a couple of alternative team to which to take his talent... and all that PDVSA money.

As Bianchi heads down the pitlane, Maldonado posts the first time of the weekend, the Venezuelan stopping the clock at 1:36.969.

Perez is another early riser, the Mexican under a lot of pressure to up his game. He posts 37.483 to go second ahead of Bianchi (38.389).

While Maldonado improves to 36.178, Perez posts 35.871. Elsewhere, Ricciardo, Chilton, Vergne, Van der Garde and Kovalainen head to work.

Game over for Bianchi has gone into the barriers at Degner, the Marussia driver losing the back end after running over the kerb at the exit to the first part of the corner.

As the red and black car is lifted from the track, swinging precariously, Webber leaves his garage. Perez improves to 35.450.

On his first flying lap Webber goes second (35.586), ahead of Ricciardo. Moments later a 35.968 sees Raikkonen go third with Hulkenberg posting 36.008 to go sixth.

Just a week after all that traction in Korea, Hulkenberg complains that he is struggling for grip. Good news for Hamilton and Alonso therefore.

Webber improves with a 35.208 to go quickest, with teammate Vettel going second (35.217) moments later. Raikkonen improves to third, with Massa going fifth and Button sixth. Next time around the Brazilian goes quickest (35.126).