Ahead of today's sole free practice session, the air temperature is 22 degrees C and the track temperature is 17 degrees. It's bright, fresh and sunny, a typical Monza morning.

While the McLarens had the edge in yesterday's opening session, it was Sebastian Vettel and the Ferraris who appeared to have the upper hand in the afternoon.

After an intriguing gamble yesterday, McLaren continues to hedge its bets this morning with Hamilton and Button’s cars running entirely different packages in terms of downforce. Basically, Button ran with the F-duct and high downforce configuration, while Hamilton ran without the F-duct and a low downforce configuration.

Having failed to drawn any serious conclusions from yesterday's back-to-back running - the two were separated by just 0.056s - McLaren will continue running its drivers on differing strategies this morning and possibly for the remainder of the weekend.

While the Woking outfit remains undecided about the F-duct, most of its rivals - including Toro Rosso, which is running its version for the first time - will continue with their low downforce strategies.

While Vettel was quickest in the afternoon, teammate Webber was sidelined by a water pressure issue and missed the last seventeen minutes of running.

Tyre options this weekend are hard (prime) and soft (option), however, Bridgestone admits that overall there was little to choose between them based on yesterday's activity.

The lights go green and di Grassi leads the way, ahead of Kovalainen, Petrov, Yamamoto, de la Rosa and a whole load of others. As Massa and Schumacher head down the pitlane, Ferrari president Luca di Montezemolo is surrounded by journalists and photographers in the paddock.

As Webber returns to the pits the green fluorescent high visibility flow paint on the rear of the car is very much in evidence. The Milton Keynes crew appear to have been very, very generous in terms of the amount of paint applied.

Ten minutes into the session, following several minutes of total inactivity, Glock, di Grassi and Schumacher give the fans something to watch.

As he completes his first flying lap (25.857), Schumacher is told to try his drink button. Glock posts 28.540 and di Grassi 29.127.

As Schumacher raises the benchmark with a 25.026, Vettel completes another installation lap. Meanwhile, Kubica, Button and Hamilton head down the pitlane.

Kubica posts 24.966 to go quickest but this is soon eclipsed by Button who crosses the line at 24.959. Moments later a 24.100 sees Hamilton take the top spot with the high(er) downforce package

Next time around Kubica posts 24.103, Button 23.959 and Hamilton 23.076, the 2008 champion around 0.8s quicker than the 2009 version.

Buemi goes fourth (24.519), ahead of Schumacher, Liuzzi and Hulkenberg.

As Button closes to within 0.65s of his teammate, Hulkenberg goes third. Elsewhere, Buemi goes quickest in the first sector however, a weak final sector sees the Swiss remain fifth.

Vettel goes sixth with his first effort, the Red Bull driver crossing the beam at 24.622. Button closes to within 0.036s of Hamilton only for the 2008 champ to improve with a 22.954.

Vettel runs wide coming out of the second Lesmo, as teammate Webber goes eighth with a 24.394 on his first flying lap.

Having gone quickest in S2, Vettel improves to third with a 23.210. Moments later Webber makes it a Ferrari 3-4 when he posts 23.603.

Next time around Vettel and Webber both improve taking second and third, thereby splitting the two McLarens. Hulkenberg is fifth, ahead of Kubica, Buemi, Barrichello, Alguersuari and Kobayashi.

Having shaken hands with di Montezemolo, Massa and Alonso are both on track. After half-an-hour the Ferrari duo have yet to post a time. The Brazilian subsequently posts 23.886 to go sixth while the Spaniard posts 24.095 to go eighth. With 26:00 on the clock all but Jarno Trulli have posted times.