Ahead of today's second practice session, the air temperature is 29 degrees C, while the track temperature is 41 degrees.

In many ways it was business as usual this morning, Nico Rosberg and Lewis Hamilton topping the timesheets.

However, behind the two silver cars - albeit around a second off the pace - were the two Ferraris, Sebastian Vettel and Kimi Raikkonen appearing to benefit from an engine upgrade this weekend which sees the Italian manufacturer use the last of its tokens.

Reinforcing the idea that the engine is a move forward, Hass drivers Romain Grosjean and Esteban Gutierrez, who also have the upgrades, were sixth and ninth.

Sauber, on the other hand, which hasn't received the upgrade yet, was 15th (Ericsson) and 19th (Nasr).

As expected, Red Bull is struggling, a combination of the total lack of grunt from the Renault engine and the fact the chassis isn't best suited to this kind of track. The fact that the Renault duo are 21st and 22nd shows just how weak the French power unit is here.

The fact that Pirelli is once again supplying its prototype tyres means that at this stage we don't really know where we are tyre-wise.

Having handed to car over to Alfonso Celis this morning, Nico Hulkenberg is back in the cockpit this afternoon.

The lights go green and Wehrlein leads the way, followed by Gutierrez, Raikkonen, Magnussen, Ocon and Palmer.

As Magnussen gets it wrong at the first chicane, Raikkonen (medium) serves notice of Ferrari's intentions, the Finn posting 25.153 to get things underway. Wehrlein posts 27.358, only to be demoted when Vettel (softs) bangs in a 24.456. The Ferrari duo are clearly up for it.

As Grosjean complains that the rear of his car is less stable, Rosberg heads out on the medium rubber, the German subsequently posting 24.752 to go second.

Shortly after, Hamilton, on the softs, goes quickest with a 23.732, while Bottas (soft) takes fourth with a 25.007.

"I lost power through the exit of the last corner," Nasr tells his team.

As Button heads out, the Briton subsequently going seventh with a 25.364, teammate Alonso doesn't look as though he's going anywhere anytime soon as the team attempts to fix the hydraulic leak that arose at the end of FP1.

"I'm really struggling with understeer in 6 and 7," complains Grosjean, "anything we can do?"

Verstappen's first flying lap sees the Dutchman go seventh (25.259), like most of the drivers he is on the soft rubber as opposed to the medium of Rosberg and Raikkonen.

Vettel switches to the supersofts as Gutierrez, also on the red-banded rubber, posts 24.762 to go fourth. However, moments later both are demoted when Ricciardo (softs) posts 24.115.

As Vettel goes quickest in S2, going on to post 23.254 and thereby take the top spot, more and more drivers switch to the supersoft including Hamilton.

Unsurprisingly, the Briton raises the bar with a 22.801, teammate slotting in just behind with a 22.994.

"I don't think these tyres can do another lap," says Hamilton as he dives into the pits.

With just over an hour remaining, Alonso heads down the pitlane, the Spaniard, using every last centimetre of track, subsequently posting 25.107 to go tenth.

As Ocon stops at T6 the VSC is deployed as the Manor is pushed to safety.

As the VSC is withdrawn, Raikkonen wastes no time in taking stepping up the pace, the Finn, now on supers, posting 23.502 to go fourth.

At 'half-time', it's: Hamilton, Rosberg, Vettel, Raikkonen, Ricciardo, Verstappen, Bottas, Grosjean, Button and Massa.

As ever, attention now switches to Sunday as driver begin their long runs on high fuel.

Oh dear, more woes for Alonso. The Spaniard was heading down the pitlane on supers when his car ground to a halt, his crew runs to his aid. "The car was not pulling, clutch slip" he tells his team, suggesting the hydraulics issue has not been resolved.

In the paddock, Bernie Ecclestone, who is accompanied by his old mate Flavio Briatore, is greeted by Monza regular Arturo Merzario.

As the Mercedes duo trade times in the mid to high 1:26s, Alonso heads out again, this time with no issues. Thus far he has only completed 6 laps.

Rosberg is told to follow the warnings on his dashboard.

Asked to report on his car after the team has made numerous changes, Kvyat dryly responds that it is "still the same".

"We're seeing some interesting long-run data," reveals Pirelli, "supersoft looks set to have a longer life than we saw at Spa."

Check out our Friday gallery from Monza, here.