Ahead of today's second practice session, the air temperature is 21.5 degrees C, while the track temperature is 37.3 degrees. The heavy cloud cover of earlier has given way to blue skies and sunshine, but this is England and it can all change quite quickly.

A light rain shower combined with the greasy new track surface made for some fun and games in FP1, but this didn't explain Romain Grosjean's bizarre crash as he left the pits and the even more bizarre lap that followed as he shed bits of his car around the track.

The resultant VSC, combined with the red flag that followed Kimi Raikkonen's engine issue went a little way to explaining what was quite an odd, pretty uneventful session.

Though there were a number of spins, there were also long periods of inactivity, with most appearing to treat it as an outright test session.

Pierre Gasly topped the timesheets, 0.456s quicker than second-placed Valtteri Bottas, but rather than signalling a much-needed revival from the Frenchman it appears more indicative of the fact that nobody was really pushing that hard.

That should all change his afternoon, as the temperatures rise and the track begins to rubber in.

The lights go green, and a couple of minutes later, Raikkonen, who has had his engine changed over the break, leads the way. He is on the softs.

Asked about the new track surface, Verstappen replies: "It's good, it has more grip than we had before. It was getting faster and faster."

As Raikkonen posts the first time of the afternoon (31.868), Sainz, Magnussen and Norris head out.

Of the first wave, Magnussen goes quickest (29.595), like the other runners thus far the Dane is on mediums.

A 29.413 sees Kvyat go top, as teammate Albon goes wide at Brooklands, seen of numerous offs earlier.

As Norris goes quickest (28.331), Gasly is the first of the big guns to head out, The Red Bull driver is on mediums.

As the Frenchman comes towards the end of his first flying lap, Bottas and Hamilton head out. Gasly posts 29.296 to go third.

As Bottas and Hamilton trade fastest sectors, Leclerc and Verstappen are also looking very quick.

Bottas posts 27.191 and Hamilton 28.006. Verstappen subsequently splits them with a 27.756, while Leclerc posts 27.810.

A brief moment for Kubica in T18 as Bottas is told that the track is around "half-a-second off" at present.

Perez, Stroll and Ricciardo are running the hards, while the Williams pair are on softs. The rest are on mediums.

Gasly goes second with a 27.667, suggesting that this morning wasn't a flash in the pan. Bottas, meanwhile, has consolidated his position with a 27.031.

Reporting understeer, Ricciardo goes 14th on his hards (29.143).

A 27.603 sees Verstappen go second, as Vettel and Grosjean remain the only drivers yet to post a time.

Bottas ups the ante with a 26.781, which puts him 1.225s ahead of his teammate.

"There is something wrong with the front-left," reports Leclerc as he heads into the pitlane.

Vettel's first flying lap - on the mediums - sees the German go 13th with a 28.687.

"I need something which gives me more rear support," says Verstappen as he reports "oversteer at the front".

Vettel improves to fifth with a 27.831, albeit 1.050s down on Bottas.

Just after the half-hour, Norris is the first driver to switch to the softs. Shortly after, Bottas also switches to the red-banded rubber.

As Bottas begins his first flying lap on the softs, more and more drivers head out sporting the same compound.

Meanwhile, goes wide through the Maggotts complex thus ruining his lap and not doing his tyres any good.

While Bottas aborts his lap, Leclerc and Hamilton look set to improve. The Briton posts 26.801 to go second, while the Monegasque goes third with a 26.929. having been quickest of all in S1.

Forty minutes in and Grosjean finally heads out, though it's unclear why we haven't seen him before.

The wind has picked up, with T9 (Copse) proving particularly difficult, though the Maggotts/Becketts complex is also proving difficult, as a number of drivers, including Hamilton, discover in quick succession.

A minor improvement for Bottas (26.732), which puts him 0.069s clear of teammate Hamilton.

"I've got an anti-stall, please confirm," says Russell, who appears to have a gearbox issue. He subsequently pits.

Sainz improves to seventh (27.987), ahead of Albon, Magnussen, Ricciardo and Hulkenberg. Moments later, all are demoted when Norris goes sixth with a 27.546.

Just across the road from their factory, the Racing Point pair are struggling in 16th and 17th.

That said, Perez subsequently improves to tenth with a 28.002.

Replay shows Norris and Hamilton taking wild rides as they run wide in Maggots, the nearby wind sock now horizontal.

"Do you want to come in for a front wing adjustment," Verstappen is asked. "It's not that," he replies. "Do you want to stay out?" "Yep," he responds.

With thirty minutes remaining, attention now switches to Sunday and the longer runs.

Kubica's car is covered with pink flo-vis as Williams seeks to make up ground to its rivals.

As Hamilton continues with his race sim, Mercedes reports a "car issue", thought to be spark plug related, for Bottas, while at Williams Russell appears to have a "gearbox issue".

On the longer runs, the Red Bull pair are clearly unhappy with their tyres. "There's a band opening up on the left-front," warns Verstappen, "it's going quite quickly". Indeed, his fronts, which are 11 laps old, are showing clear signs of graining.

As Ricciardo stops on track, the VSC is deployed. Replay shows a sudden loss of power in the Maggots complex. "Okay it's switched off, I have a problem," says the Australian.

Meanwhile, Bottas just left the pits, the Finn unclear what speed he should be doing under the VSC.

"Back to mode six, we've run out of battery for some reason," Albon is told.

With just under ten minutes remaining, the Mercedes pair switch to mediums.

The Bulls aren't alone in their tyre issues, as Leclerc also reports graining with his fronts. He subsequently pits for fresh rubber, changing from mediums to softs.

Meanwhile, Hamilton suddenly goes quickest in the opening sector, before easing off in S2.

Leclerc goes cross-country at Brooklands.

On the evidence thus far, while Bottas is quickest, teammate Hamilton has the edge in terms of race pace, while Verstappen, appears to have a little in hand over Leclerc and Vettel. Indeed, it's rare to see Gasly ahead of his Red Bull teammate in both sessions.

The session ends. Bottas is quickest, ahead of Hamilton, Leclerc, Vettel, Gasly, Norris, Verstappen, Sainz, Albon and Perez.

Kvyat is eleventh, ahead of Magnussen, Raikkonen, Ricciardo, Hulkenberg, Stroll, Giovinazzi, Grosjean, Kubica and Russell.

So, not for the first time, Mercedes is looking good, while, also not for the first time, tyres look set to play a major part as the weekend develops.

Check out our Friday gallery from Silverstone, here.