Barcelona F1 test day one

02:32 Driver, Team, Time, Tyre
Hamilton, Mercedes, 1m25.409s, M
Vettel, Ferrari, 1m24.939s, M
Bottas, Williams, 1m26.091s, M
Ricciardo, Red Bull, 1m26.044s, M
Celis, Force India, 1m26.298s, S
Palmer, Renault, 1m29.356s, M
Sainz, Toro Rosso, 1m27.180s, M
Ericsson, Sauber, 1m27.555s, M
Button, McLaren, 1m26.735s, S
Wehrlein, Manor, 1m28.292s, S
Grosjean, Haas, 1m28.399s, M

20:35 That's it from Autosport live for day one of F1 2016 testing. Our journalists have headed into the paddock to find out the stories behind the laptimes from today, and you'll find plenty to read on autosport.com through the evening. We'll be back online shortly before 8am UK time tomorrow for day two from Barcelona, thanks for joining us.

20:33

20:21 Here's our report from the first day of F1 2016 pre-season testing at Barcelona, with Ferrari leading the way in the hands of Sebastian Vettel but Mercedes catching the eye on the lap count:

Barcelona F1 test: Sebastian Vettel and Ferrari top day one

Sebastian Vettel finished the opening day of 2016 pre-season Formula 1 testing fastest for Ferrari, but it was reigning champions Lewis Hamilton and Mercedes who racked up the laps

20:20

20:11

20:08

Vettel ends the first day of testing fastest for Ferrari (XPB)

20:07 Lap count:

Hamilton, 156Ericsson, 88Ricciardo, 87Button, 84Bottas, 80Vettel, 69Celis, 58Sainz, 55Wehrlein, 54Palmer, 37Grosjean, 31

20:04 So Ferrari ends the first day of pre-season testing on top, like it did last year, but Mercedes catches the eye with some seriously impressive mileage, like it did last year.

20:03

20:00 And Palmer does improve on his last lap to a 1m29.365s on mediums. But he's still last.

20:00 And that's it - the chequered flag flies. The one car that might improve is Palmer in the Renault.

19:59 Button is the quickest of those currently lapping. He's in the low 1m28s bracket. But there's no sign of any late fast times.

19:58 Toro Rosso's chief race engineer Phil Charles explains an early finish to its first day of running, with Sainz stuck on his race number of 55 laps after a promising start to the day: "During one of the early runs this afternoon we saw something in the data that’s a little bit strange in the gearbox oil system, so as a precaution we decided to stop the car. We will now take our time to understand it and hope for an even better day tomorrow.”

19:56 Hamilton, Ricciardo, Bottas, Celis, Button and Ericsson are all on track in the closing minutes

19:55

19:54 Celis improves to a 1m26.298s. He's fifth fastest now.

19:53 Palmer shaves 0.013s off his time. Unsurprisingly, that hasn't made a big dent in the advantage of over two seconds the Haas has over the Renault.

19:51 Celis is out on the softs, so we could see an improvement from him. He needs to find just over two tenths to move up to fifth.

19:51 Ricciardo heads back out in the clockwork-powered Red Bull. He's third fastest currently.

19:51 We'd argue that Ferrari tweet should read 'behind the screens' given how secretive the team has been today in the pitlane.

19:50

19:48

19:48 Palmer improves to a 1m31.019s in the Renault. But he's still 11th and slowest.

19:46 Bottas, Wehrlein and Palmer are on track at the moment.

19:45 Laps completed:Hamilton, 152Ericsson, 85Button, 79Ricciardo, 78Vettel, 69Bottas, 69Sainz, 55Celis, 50Wehrlein, 47Grosjean, 31Palmer, 28

19:43 Vettel has not done a huge amount of laps this afternoon in the Ferrari, but he's still fastest by just under half a second from Hamilton.

19:42 Bernie Ecclestone has caught the eye with some scathing comments about the state of F1 today, but Christian Horner thinks he's just frustrated about not being able to force through changes in the way he could before F1 became so democratic

Red Bull F1 boss Horner senses Bernie Ecclestone's 'frustration'

Red Bull team principal Christian Horner believes Bernie Ecclestone is "frustrated" following the Formula 1 supremo's latest denigrating comments against the motorsport series he helps run

19:42 And Hamilton completes his 150th lap. He would have raised his bat to the sparse crowd, but for the fact that he will know cricket-based metaphorical celebrations do not translate to a Spanish audience.

19:41 And Button improves to a 1m26.735s. He's on the softs.

19:41 Button sets his personal best in sector two. You can probably see where this is going...

19:40 Button sets his personal best in sector one in the McLaren-Honda.

19:39 And Hamilton starts his 150th lap of the day.

19:38 There's a battle raging for least laps completed today - Grosjean in the Haas has just drawn level with Palmer in the Renault on 27 laps.

19:36 Looks like Hamilton will hit 150 laps for the day in the Mercedes as he has just gone onto is 148th lap. He's currently lapping in the low 1m29s bracket.

19:35 Ricciardo returns to the pits. Hamilton, Celis and Wehrlein are still on track.

19:14 Palmer is also out in the Renault.

19:14 Yes, it is the Red Bull of Ricciardo. As you would expect from a car that is apparently powered by a watch (Tag Heuer, remember, not Renault) it stuttered down the pitlane. But seems to be on song now.