@LD: Rules change in F1 all the time, though.
Hamilton goes P1 by exactly four tenths. Vettel, meanwhile, leaps into P3.
Hamilton went purple in all three sectors on that lap. Very impressive.
Seeing a replay of Vergne carrying too much speed into Turn 8 and running across the tarmac.
Only four tenths between Maldonado and Ocon, who beat Max Verstappen to the Formula 3 title.
@PeteGill: For those of you asking, that's why Bottas couldn't continue in this session. And also why losing bodywork in a race would be a race-ending issue.
Lots of work going on in McLaren's garage on Button's car.
Only Stevens yet to set a time.
@KeenFan: I don't know. If it was anyone else, no-one would care, but people seem to think if Hamilton wears it he's a bit of a prat. In the day and age of the sheltered PR sportsman/F1 driver, I find it quite refreshing that Hamilton doesn't seem to care what people think about him.
Vettel puts his hand up to Magnussen as he comes up to the slow McLaren at Turn 8. Magnussen has none of it and refuses to yield through the corner.
Vettel has his old Red Bull helmet on today, the blue and silver lid he wore during his days at Sauber. It says 'Danke' on the top. This will be an emotional farewell for Vettel at the track where he claimed his first world title with Red Bull.
Rosberg's latest time puts him P1, one tenth quicker than Hamilton. Going to be interesting to see the rules on track limits at the penultimate corner.
Toro Rosso doing its usual trick of showing some great pace on Friday.
Hulkenberg slots into seventh with his latest run. He's half a second up on Perez.
@Me: He had an issue on his car after just one installation lap and has not emerged from the garage yet.
Magnussen is getting a new wing on his car. Looks like it's another 2015-spec wing, the one designed by ex-Red Bull guru Peter Prodromou. And unsurprisingly it looks a lot like a Red Bull wing.
Hulkenberg reports a lot of improvement on the second run on the soft tyres as the track gets more rubbered in.
Replays show Ocon missing the apex at Turn 12.
Hamilton leaps back into P1 by nearly two tenths.
@kathy: I don't know, possible, but then Vettel seemed to have the lion's share of luck at Red Bull over the last four seasons so swings and roundabouts. Ricciardo is clearly a class act and proof Red Bull's young driver programme isn't just about Vettel. I think the team unearthed a future world champion this year. Vettel needs a change of scenery, too.
Alonso the best of the rest this morning but a massive 1.7s down on Mercedes. The gap between the Mercedes just 0.133s. Looks like it could be a two-horse race out in front again....
@NotanF!fan: That would be seven wins - Alain Prost (1988), Kimi Raikkonen (2005) and Michael Schumacher (2006).
@duggo: One. We are having an issue with our timing screen.