Ahead of today's second session the air temperature is 19 degrees C, whilst the track temperature is 40 degrees. It remains bright and sunny.

As expected, Mercedes ruled the roost this morning, Nico Rosberg edging out teammate Lewis Hamilton by just 0.029s.

However, also as expected, it is the fierce competition between those behind the Silver Arrows that is interesting.

Whilst Red Bull had limited running and has yet to show its hand, Williams, Ferrari and Toro Rosso were covered by just 0.5s, the Faenza pair, Verstappen and Sainz, also the busiest.

Grosjean's morning was compromised by a fluid leak which McLaren suffered a system control data issue, though both drivers did at least set times.

Over the lunch break Red Bull changed the engine in Ricciardo's car, the Austrian team "hoping" to get him out this afternoon.

Facing a whole ranges of issues there was no sign of the Marussias, whilst Sauber is still involved in its very messy legal tangle with Giedo Van der Garde and remained safely behind the shutters.

There are two DRS zones, detection is 13m before T14 with activation 30m after T16 and 32m after T2. Tyre compounds available are medium and soft, though we only saw the prime compound this morning.

The lights go green first out is Nasr... in the Sauber. He is followed by Ericsson in the second car.

Another early bird is Grosjean, the Lotus driver setting a hard pace on his out lap.

Raikkonen posts the first time of the day 1:39.368 but this is soon beaten by Grosjean who crosses the line at 33.310.

A 30.451 sees Vettel go top as Grosjean goes cross country at T3.

Red Bull confirms that Ricciardo will not take part in this session due to his engine change.

Massa will also sit out this session, the Williams driver suffering a water leak on his power unit. Sounds painful.

Vettel and Raikkonen trade quickest laps, the German raising the bar with a 29.801.

Just fifteen minutes into the session and already there are ten scores on the doors.

As Hamilton splits the Ferraris with a 30.096 he reveals that his DRS is not working. Elsewhere, a minor excursion for Maldonado at T15.

The session is red flagged at 16:46 as Magnussen goes off at T6. The Dane appeared to carry too much speed into the corner and simply skated across the gravel trap and ending up in the barriers. Not much obvious damage to the McLaren - where have we heard that one before - as it is lifted out of the way. Asked if he's OK, Magnussen says that he's "fine".

As the car is lifted to safety the damage to the left-front suspension is noticeable.

Currently the order is: Vettel, Hamilton, Raikkonen, Grosjean, Verstappen, Kvyat, Maldonado, Sainz, Perez and Magnussen.

At 16:53 the session resumes and Bottas is first out of the blocks.

Button goes thirteenth with a 34.071 as Raikkonen goes quickest in S1 the Finn having switched to the option rubber. Vettel is also on the softs.

Raikkonen posts 28.842, having gone quickest in all three sectors, as Rosberg complains he has no information regarding his gears.

Vettel (softs) leapfrogs his teammate with a 28.412, taking 0.430s off the Finn.

Rosberg, who is also on mediums, goes third (29.937), 0.683s off Vettel's pace, posting PBs in all three sectors.

More problems for Sauber, there is clearly something wrong with the left-rear suspension. The car is dipping in one corner and smoke is billowing from the back where something is rubbing. A replay reveals that he possibly damaged it on the kerb coming on to the main straight.

A big moment for Grosjean who momentarily loses the Lotus and almost collects the slow-moving Ericsson.