Ahead of today’s second free practice session the air temperature is 30 degrees C, while the track temperature is 39 degrees. It remains hot, very hot.

Sebastian Vettel headed Red Bull teammate Mark Webber in this morning’s session, ahead of Kimi Raikkonen, Fernando Alonso and Romain Grosjean, with Jenson Button also looking good in the McLaren.

A couple of drivers appeared to be struggling for grip, most notably the Williams and Toro Rosso duos and Lewis Hamilton. Paul di Resta was also well down the timesheets, some fearing that Force India, more than any other team, will pay the price following the changes to the 2013 tyres.

Having handed his car over to Rodolfo Gonzalez this morning, Max Chilton is back in the second Marussia this afternoon.

Tyre options this weekend are medium (prime) and soft (option), this event witnessing the revised Pirellis which feature the 2012 structure with a 2013 compound – as tested at Silverstone last week.

There are two DRS zones – one on the main pit straight, the other from Turn 1 to Turn 2 – but just one detection point, at the entrance to Turn 14, the final corner.

Having missed out on this morning’s session, Chilton is first out of the blocks when the lights go green.

No sooner has Chilton posted 29.373 than he is joined by thirteen other drivers, including Rosberg and Hamilton, the action getting underway surprisingly early.

Ricciardo and then Bottas go quicker, the Finn crossing the line at 25.191.

As in FP1, the Toro Rossos drivers are struggling, Vergne running wide at T7 and Ricciardo at T4.

On his first flying lap Hamilton posts 24.137 to go quickest, ahead of Button, Maldonado and di Resta.

As Webber suffers a major lock-up, teammate Vettel goes quickest with a 22.484, that’s quicker than he went this morning.

“Do you want to talk about the car balance on the radio or not,” asks Button – over the team radio. Clearly the team does.

Sixteen minutes into the session, with the Ferrari duo yet to show, Webber goes second and Raikkonen third. Still no sign of the option rubber.

As the Ferraris finally head down the pitlane, Hamilton posts a 22.991 to go fourth.

Alonso goes fifth and Massa third, the Spaniard subsequently eclipsing his teammate with a 22.861.

Pic is first to make the switch to options (soft), followed by Bianchi, Vergne and Vettel.

While the others show little sign of improving, Vettel immediately goes quickest in S1. He’s quickest again in S2, finally crossing the line at 21.264, that’s 1.220s quicker than his previous best. But for a small mistake in S3 he could have gone even quicker.

Webber (softs) closes to within 0.044s of his teammate as Rosberg posts a PB in S1, the German having also switched to the softer rubber. He subsequently goes third (21.991), 0.727s off Vettel’s pace, having posted PBs in all three sectors.

Raikkonen runs wide at T4 while Hulkenberg locks-up, the Finn still running on the harder rubber.

Sauber looking good as Gutierrez goes sixth and Hulkenberg fourth, though moments later PBs in all three sectors see them both demoted when Hamilton (softs) posts 21.802 to go third.

Gutierrez improves to fifth only to be demoted (again) when Massa posts a 21.701 on the softer rubber.

With 50 minutes remaining, the Lotus duo, Force India duo, Williams duo and McLaren duo have yet to make the switch to options.

Alonso closes to within 0.162s of Vettel, the Spaniard appearing to have a little bit in hand.