Ahead of today's second practice session, the air temperature is 27 degrees C, while the track temperature is 39 degrees.

Jenson Button led a McLaren 1-2 in this morning's session, ahead of Mark Webber, Nico Rosberg, Michael Schumacher and local hero Kamui Kobayashi.

Rosberg ground to a halt late in the session with an oil pressure problem, Mercedes reliability continuing to cause concern.

The lights go green and Vergne is first out followed by Perez, Kovalainen and Ricciardo.

Tyre compounds are hard (prime) and soft (option), though we have yet to see the softer rubber today.

Within four minutes of the session getting underway, there are 17 drivers on track.

It's an early bath for di Resta who goes off into the barriers at the entry to Spoon. The session is immediately red flagged. Replay shows the Scot getting his two outside wheels on to the dirt at the side of the track and losing it and slamming sideways into the tyre wall. He sustains a fair amount of damage to his car but is OK.

After just two minutes the session resumes as Mercedes reports that it is changing the engine in Rosberg's car. The German, and his (retiring) teammate are the only drivers yet to mane an appearance, Schumacher having work done on his suspension.

In no time at all there are a number of names on the timesheets, Grosjean (34.514) heading Vettel, Perez, Vergne and Ricciardo. However, a 34.287 sees Alonso take the top spot.

A 34.398 sees Hamilton go second as di Resta arrives back in the Force India garage. Elsewhere, a lock-up for Hamilton in the chicane.

Not for the first time this season, Raikkonen has a problem with his KERS - its not working - while the team has opted not to use its controversial (DRS) device. As the Finn returns to the pits he is warned that the KERS is unsafe… rubber gloves at the ready in the pitlane.

Kovalainen and Kobayashi both go cross-country, the Sauber driver enjoying a particularly bumpy ride over the gravel at Turn 7.

As Perez goes quickest in S1, Webber goes fourth overall (34.481), only to be demoted when Button posts 34.150 to go quickest.

An absolutely massive blister on the right front tyre on Maldonado's Williams. Absolutely massive.

As Webber improves to second, Perez is warned that he too has a KERS issue, though his is to do with "battery level".

After thirty minutes, Petrov is the first driver to switch to the softer rubber. The Russian, who has yet to secure a seat for 2013, is currently seventeenth (37.570).

Massa, also switches to softs as on-board reveals Vettel going through 130R full throttle and subsequently crossing the line at 34.080 to go quickest. The German was on pole here last year - the Button won the race.

Kobayashi leaves the Sauber garage on softs, the Japanese eager to improve on tenth (34.873).

After a 'slow' lap, Vettel improves with a 33.961, as Kovalainen is the latest driver to lock-up.

On the softer rubber, Kobayashi goes quickest in S1. The Japanese subsequently crosses the line at 33.983 to go second though its clear he has room for improvement.

Now on the softer rubber, Button goes quickest in all three sectors, the McLaren driver raising the benchmark with a 33.349 which puts him 0.612s clear of Vettel.

Grosjean (softs) improves to fifth and then goes quickest (33.107), having posted purples in the first two sectors.

At 'half-time', it's: Grosjean, Button, Massa, Vettel, Kobayashi, Perez, Webber, Alonso, Maldonado and Hamilton.

Massa's Ferrari bouncing about as he closes in on former teammate Schumacher, while Vettel, now on softs, ups the ante with a 32.836. On a subsequent lap Massa runs wide, his F2012 looking a real handful.