Mercedes driver Nico Rosberg carried on where he had left off in China by setting the fastest time of the day during free practice in Bahrain, but Pirelli admits that it still has some way to go before fully understanding the limits of its tyres in desert heat.

Rosberg set his fastest time of 1min 32.816secs on the soft tyre during a second practice session characterised by high track temperatures, which climbed progressively during the day and peaked at around 31 degrees centigrade ambient. As the session went on, track temperature began to fall from a high of 40 degrees, during which Rosberg set his fastest time. With similar conditions likely for qualifying and the race, all teams ran both compounds extensively during FP2 in order to accumulate as much data as possible.

Williams driver Pastor Maldonado was the first to switch onto the soft tyres, 20 minutes into the second session, and was followed progressively by the other runners. With half an hour to go, many teams decided to concentrate on long runs with high fuel, although some split the work by running one car on soft tyres and the other on mediums to cover every possibility.

Rosberg once again demonstrated his ability to get the most out of his tyres at the peak of their working range, however, setting a fastest time that was nearly half a second faster than second-placed Mark Webber. Lewis Hamilton had earlier set a fastest time of 1min 33.572secs in the middle of the morning session, using the medium tyres, while Force India - which opted not to contest FP2 in order to avoid expected anti-government protests - was the only team to use the soft tyres in the morning, placing third with Paul di Resta and sixth with Nico Hulkenberg.

The Sakhir circuit reverted to the original layout that had last been used in 2009, before a longer loop was added for the 2010 race between turns four and five. This gives the circuit a faster and more flowing configuration, with 15 corners as opposed to 23, and puts an emphasis on traction as well as the front-left tyre in particular.

A typical hallmark of Bahrain is the sand that blows onto the track from the surrounding desert, and this was very much in evidence during the first free practice session, causing the cars to slide more, increasing thermal degradation and slowing lap times. The issue, however, was to a lesser extent than many of the teams had anticipated.

"The sand on the track, a phenomenon that we are well aware of following our tests in Bahrain in the past, limited the useful running in the morning, but it was a much busier session in the afternoon, with all the teams running both compounds in order to make up for any lost time earlier," Pirelli's motorsport director Paul Hembery said.

"The teams will all have been looking closely at the effect of track temperature on performance, which is going to form an integral part of their strategy for qualifying and the race, as well as monitoring degradation. From what we can see so far the pace of both compounds is around 0.6secs apart and degradation is in line with expectations.

"But we still have a lot of data to go through tonight before we can accurately predict how long the stints are likely to be on each tyre, as this is the first time that we are here in race conditions."