It certainly makes things interesting for tomorrow. Can McLaren sort things out and get some decent running in on the final day of testing? Join me at 08:00 GMT tomorrow to find out.
In total for testing McLaren have managed less than 200 laps. Every other team has managed well over 400, with Mercedes leading the way with over 800. Worrying times for McLaren?
Day three testing times in full
1 Pastor Maldonado (Ven) Lotus-Mercedes 1:24.348
2 Max Verstappen (Ned) Toro Rosso-Renault 1:24.739
3 Lewis Hamilton (GB) Mercedes 1:26.142
4 Marcus Ericsson (Swe) Sauber-Ferrari 1:26.340
5 Sebastian Vettel (Ger) Ferrari 1:26.407
6 Daniil Kvyat (Rus) Red Bull-Renault 1:26.589
7 Felipe Massa (Brz) Williams-Mercedes 1:26.912
8 Pascal Wehrlein (Ger) Force India-Mercedes 1:27.333*
Mercedes: Job done! 101 the total for Lewis Hamilton today - he's powered through these past couple of sessions!
Chequered flag
Out comes the chequered flag to bring day three to a close. Five drivers got over 100 laps under their belt, a figure Jenson Button can only look on enviously at after a frustrating day for McLaren.
Pastor Maldonado finishes fastest for the day.
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Mercedes: That's his century! 100 laps hit for Lewis Hamilton Howzaaaat! ;)
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Jenson Button completes a lap, heads in, heads back out but soon heads back in again.
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That's better, a 1:27.556 is almost two seconds quicker than Jenson Button's best effort, so Valtteri Bottas is up into ninth.
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Ah, a late timed lap for Valterri Bottas but it is not enough to lift him off the bottom of the timesheet as he clocks 1:38.067.
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WilliamsCopyright: Williams
Williams: Final 10 minutes and Valtteri Bottas heads out with a clear visor as the light fades.
Jenson Button heads out, he'd certainly welcome a few trouble-free laps, and he is quickly followed by Marcus Ericsson, Valtteri Bottas and then Pascal Wehrlein.
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The green flag is waved and 10 minutes remain for teams to rattle up a few late laps.
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Force India: Red flag halts proceedings. It may be a bit of a scramble for the pit lane once the session goes green again! Every lap counts.
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It was the Toro Rosso that brought out the red flag and the recovery truck trundles over to lift Max Verstappen's car. Should be enough time to squeeze in a few more laps before day three of testing comes to an end.
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Max Verstappen stopped just before Turn 1, while Jenson Button also came to a halt at the pit exit.
Red flag
McLaren head back out, but there is a red flag...
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A bit more activity on the circuit as we enter the final 30 minutes with Sebastian Vettel increasing his lap total for the day in the Ferrari. Pascal Wehrlein, in the Force India, and Toro Rosso's Max Verstappen are also out there.
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Force India: Pascal's tally is up to 77 laps, a very good haul for the youngster who has been through a plan of setup work and longer runs. The crew has completed some routine checks after the latest long run, so we're ready to put in some extra laps before the end!
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Daniil Kvyat pops out in the Red Bull but is straight back in and once again the circuit is empty. Sensing there is little more to see today, spectators are starting to make their way home.
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Pastor Maldonado cuts a lonely figure as he weaves his way around the circuit in the Lotus - the only car on the circuit.
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Getty ImagesCopyright: Getty Images
Just over 45 minutes remaining of testing for today, will we see another appearance by the McLaren? Yes, is the answer, as Jenson Button ventures out but how many more laps can he add to the 18 he has completed today?
Completed laps on day three
1. Max Verstappen 125
2. Daniil Kvyat 102
3. Sebastian Vettel 101
4. Pastor Maldonado 94
5. Lewis Hamilton 86
6. Pascal Wehrlein 76
7. Felipe Massa 55
8. Marcus Ericsson 46
9. Valtteri Bottas 36
10. Jenson Button 18
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Nothing much going on on the circuit at the moment, with Max Verstappen and Valtteri Bottas performing pit-stop practices. Sebastian Vettel continues to increase his mileage on the circuit as he surpasses 100 laps for the day in the Ferrari.
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Tony Dickinson: Maybe this is a secret plan by McLaren to lull everyone into a false sense of security.
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Marcus Ericsson, on the soft tyres, is up to fourth with 1:26.340, and the times from third fastest to seventh fastest are separated by nine tenths of a second.
Ericsson, Max Verstappen, and Pascal Wehrlein are the drivers on the track at the moment.
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F1 journalist Dan Knutson in Barcelona: "Williams did the same thing last year - doing pit stop after pit stop with the driver coming in after each lap and therefore never setting a lap time. Valtteri Bottas has now done 34 laps doing just that. It's expected that he will do some proper timed runs before the session ends."
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Brief. Jenson Button is once again back in the pits after lap 18.
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A limited-power McLaren is guided back on to the circuit by Jenson Button.
Meanwhile, Daniil Kvyat has surpassed 100 laps for the day as he heads off on number 103. Only Max Verstappen, on 115, has managed more today.
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SauberCopyright: Sauber
Sauber: Pit-stop practice. Marcus Ericsson is now in the garage and gives feedback.
"More on McLaren's problems. It turns out our earlier suspicions were right - McLaren's delays have been caused by the same part that stopped Jenson Button on Thursday, a seal on the motor generator unit that recovers energy from the rear axle (the MGU-K). A new design was fitted to the car for today's running and Honda hoped that would fix the problem. But it has not.
"A spokeswoman said: 'After the morning session, the car fed back MGU-K issues similar to what we experienced on Thursday, so we brought it back to the garage. After a thorough check, we have decided to resume testing with limited power to the MGU-K. A new re-engineered seal is scheduled to arrive and will be applied later this evening.'"
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It looks like it is a short stay back in the garage for Jenson Button, with the McLaren seemingly set to re-enter the fray. Meanwhile, Lewis Hamilton is back on the circuit, currently lapping in the 1:26s.
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Mark Snow: Hope McLaren have not scooped the 'F12015 sunk without trace award' again before the season's even got under way.
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Valtteri Bottas is up to 30 laps without setting a time as Jenson Button heads back in at the end of lap 15.
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Jenson Button completes his 14th lap of the day and stays out on the circuit. All being well, he will have 90 minutes out there to rack up the mileage.
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...and out goes Jenson Button, his first trip on to the circuit since this morning.
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Daniil Kvyat on his race simulation, pits for softs with 12 laps to go. Meanwhile, it seems like there may indeed be some activity in the McLaren garage...
"McLaren say they hope to have Jenson Button out again 'very soon'. The team said that 'there were a number of things we had to check and some issues we had to address, which took some time'. They promise more details shortly."
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Fernando AlonsoCopyright: Fernando Alonso
No sign of the McLaren on the circuit yet, so here's a picture of a beaming Fernando Alonso stood behind the iconic McLaren MP4/4 from the 1988 season.
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Lewis Hamilton completes an 11-lap stint on medium tyres, with the majority of those laps either 1:27s or 1:28s.
Sebastian Vettel also completes a flurry of laps, heading in after his 16th in succession with those averaging in the 1:29s. He is closing in on a century of laps for the day and it is looking like being another pleasing outing on the circuit for Ferrari, despite his spin right at the start of the day.
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Valtteri Bottas has yet to clock a timed lap, despite managing 22 laps. He has spent the afternoon doing some pit-stop practice.
Jenson Button will no doubt be itching to get back out on the circuit. He has now dropped to the bottom of the timesheet as Marcus Ericsson clocks 1:28.858 to move up to eighth. He heads back in, leaving Lewis Hamilton, Sebastian Vettel and Daniil Kvyat on track.
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SauberCopyright: Sauber
Sauber: Marcus Ericsson is now on a run with medium tyres.
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Mercedes: UPDATE: 2hrs of HAMmertime remain this week - 66 laps on the board for Lewis Hamilton so far: he's on track now...
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Lewis Hamilton heads back out on the medium compound and improves on his best time from the morning with a 1:26.076. He remains third fastest, though, with Pastor Maldonado and Max Verstappen out in front.
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WilliamsCopyright: Williams
Williams: More pitstops...This time the boys prepare for Valtteri Bottas to hit his marks.
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F1 journalist Dan Knutson in Barcelona: "After a stint in the garage, Daniil Kvyat has resumed his race simulation, which had 32 laps to run. He has the medium compound Pirelli slicks on his Red Bull."
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LotusCopyright: Lotus
Jenson Button's lack of activity means he has completed just 12 laps on the third day of testing so far.
"There has still been no sign of the McLaren-Honda this afternoon, and that is not good news for the team. Jenson Button has done only 12 laps so far and although the team said earlier that the stoppage Button suffered this morning was 'planned', one has to assume something else is wrong, because McLaren need nothing more than mileage at the moment. We're trying to find out what's going on."
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Getty ImagesCopyright: Getty Images
Lewis Hamilton pits after some mid-distance runs on the medium tyre and, at the moment, there is just Max Verstappen out on track. The rookie driver's best of the day - a 1:24.739 - keeps him in second.
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Marcus Ericsson, on the medium tyre, clocks his best of the day, a 1:29.171 but it is just shy of Jenson Button's fastest and he remains bottom of the timesheet.
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BBCCopyright: BBC
F1 journalist Dan Knutson in Barcelona: "With 32 laps to go in his race simulation, Daniil Kvyat pitted and the mechanics pushed the car into the garage.
"Prior to that the mechanics had been doing a race simulation of their own and sitting on chairs in the garage. But unlike a race weekend there was no TV coverage to watch."
We're looking into the situation at McLaren, Richard, hopefully we will be able to update you soon.
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After a breather in the Lotus garage, Pastor Maldonado heads back out and he is quick, fastest of all through the first sector and...it's the fastest lap of the day - 1:24.348 on super softs.
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Frank Lopez: That size zero is yielding zero test results. Have McLaren shot themselves in the foot overcomplicating the car?
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Lewis Hamilton and Sebastian Vettel are racking up the laps, the former lapping in the 1:28s with Vettel averaging around two seconds slower. Meanwhile, Daniil Kvyat ends his long run by returning to the Red Bull garage.
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Pastor Maldonado improves again, joining pacesetter Max Verstappen in dipping below 1:25s as he clocks 1:24.917.
Valtteri Bottas, meanwhile, has six laps to his name but is yet to set a time and interestingly, no sign of Jenson Button in the McLaren on the circuit this afternoon...
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LotusCopyright: Lotus
With just under three hours left, here's an update on fastest laps and completed laps, courtesy of Lotus.
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LotusCopyright: Lotus
Lotus: Must be tiring work in the car for Pastor Maldonado - time for a quick pitlane siesta.
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Daniil Kvyat completes the 25th lap of his race simulation, 40 more to go. He is lapping in and around the 1:31 mark.
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MercedesCopyright: Mercedes
Mercedes: And the selfie king returns to the track! Sun out, medium tyres on, action!
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Lewis Hamilton has put away his camera and is out on the circuit for the first time this afternoon, medium tyres bolted on.
Pastor Maldonado, meanwhile, clocks 1:26.208 - the third fastest time of the day as Valtteri Bottas heads out for Williams. He has replaced Felipe Massa, with the two sharing testing duties today.
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Anthony Wyatt: "RE: 13:45 a political bluff or just training? It's so interesting. a game of chess, but more colours."
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F1 journalist Dan Knutson in Barcelona: "It's amusing to see that Force India has sight screens up at its garage door [see 13:45 entry]. That's the 2014 car, so the team really has no technical things to conceal. Perhaps they are just hiding that ugly anteater nose on the car."
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Red Bull RacingCopyright: Red Bull Racing
Fed up with the cold and wet weather in the UK this week? At least it is not too great over in Spain as well.
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Ten laps into his race run, Daniil Kvyat pits for mediums, heads back out and dips under 1:30, clocking 1:29.7 on the new tyres.
Sebastian Vettel is out, but only briefly as he heads back into the pits after completing a couple of laps.
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You may have been wondering where Lewis Hamilton is this afternoon. He is still in the Mercedes garage, posing for a selfie.
Lewis HamiltonCopyright: Lewis Hamilton
He tweeted: "Hope you're having a great day! Still feeling under the weather but I'm pushing for you guys."
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The sun is breaking through the clouds, prompting one or two teams to start getting things ready for a venture on to the circuit, Pascal Wehrlein one of those as his Force India rolls out of the garage.
The laps are ticking down on Daniil Kvyat's race simulation, too, with 'L61' on the Red Bull board. He has been lapping in the 1:30 and 1:31s.
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Force India: Still quiet in the garage as we wait for the track conditions to improve...
Force IndiaCopyright: Force India
There's a conspicuous addition of a driver to the car, though, so some more lappage could be on the cards soon.
Force IndiaCopyright: Force India
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F1 journalist Dan Knutson in Barcelona: "Red Bull is doing a very thorough race simulation. A crew member placed bottles of water at each of the seven seats on the pit wall where Christian Horner, Adrian Newey and the engineers sit (although they are not all out there now.)
"Daniil Kvyat did one lap and then came into the pits, stopped 50 yards away from the Red Bull garage, and shut the engine off. The mechanics then pushed the car to the garage, just as it would be pushed from the back of the grid to its starting slot on the grid.
"After a waiting period similar to what it would be on the grid before the start of the race, Kvyat then headed out with intermediate rain tyres fitted to the car, did one lap and pitted for a set of the soft compound Pirelli tyres. He is now off and running and doing the race sim."
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This morning's pitstop practice is put to good use as Daniil Kvyat pits for softs and heads back out to begin his race simulation.
Marcus Ericsson, meanwhile, is doing his best to make up for lost time with eight laps to his name so far, the best a 1:42.179.
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Mercedes: A brief exploratory foray around the circuit only for Lewis Hamilton so far following the lunch break. It's a little greasy out there...
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Marcus Ericsson is out for a cautious venture around the track, checking the conditions. Daniil Kvyat is back out too.
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Sauber: Lunch break is over. Marcus (Ericsson) is going out on intermediates as the track still seems to be damp.
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It is an exploratory lap for Daniil Kvyat on inter tyres as he heads back in and is wheeled back to the Red Bull garage.
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Everyone is briefly back in the pits, before Daniil Kvyat decides to head on to the empty circuit. He completed 34 laps this morning, spending most of his morning making practice pitstops.
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BBCCopyright: BBC
F1 journalist Dan Knutson in Barcelona: "Red Bull has a pit board with L65 on it ready to go. A race distance here is 66 laps, so it looks like Daniil Kvyat will be doing a race simulation soon."
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Pascal Wehrlein takes the Force India out on to the circuit for the first time in the afternoon session, joining Lewis Hamilton and Max Verstappen, who is on the medium tyre.
It appears some of the teams are waiting for the circuit to dry up a bit before heading out, with some areas still a little damp.
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Getty ImagesCopyright: Getty Images
The reigning world champion was able to gulp down a brew during lunch. He seems to be back on form after a bout of illness earlier this week.
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Lewis Hamilton is joined on the circuit by this morning's pacesetter Max Verstappen, who got plenty of mileage in before lunch.
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McLarenCopyright: McLaren
McLaren: The iconic MP4/4 joins us in the garage today. Looks stunning despite the grey Barcelona skies.
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Lewis Hamilton also heads out on to the circuit as Pastor Maldonado's brief foray comes to an end.
Grey skies above the circuit, and only a few spots of rain falling.
Go! Go! Go!
Right then, thanks for sticking with me over lunch and for those of you who have returned or just joined, welcome!
The afternoon session is live and out goes Pastor Maldonado.
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Romain GrosjeanCopyright: Romain Grosjean
Romain Grosjean: Preparing tomorrow's running with my engineers. Looking sunny
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Getty ImagesCopyright: Getty Images
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This is Ferrari's view on how the morning went: "Sebastian went off the track at Turn 5 on his first out-lap, but no damage was done. After that, he went on to complete 46 laps over the course of the morning, the quickest in a time of 1.26:407, third fastest overall.
"Today's programme again features aerodynamic and set-up work. As the rain intensified, the team decided to slightly modify the programme, with normal work set to resume once it's over."
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Here's a couple of shots from this morning to enjoy over your lunch.
This is Sebastian Vettel's Ferrari being recovered after an early spin...
Getty ImagesCopyright: Getty Images
...it was a busy morning for the Red Bull crew as Daniil Kvyat made a number of practice pitstops...
Getty ImagesCopyright: Getty Images
...Kvyat had flow-vis paint on the back of his helmet at one point as the team looked to see where air flowed around the helmet...
Getty ImagesCopyright: Getty Images
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After spinning off the cold track early on, it has been so far so good for Sebastian Vettel and Ferrari.
The new car has been impressive in winter testing, surely we are likely to see Ferrari team principal Maurizio Arrivabene running barefooted at some point in this season?
"McLaren have revealed why Jenson Button stopped out on track early in the morning's session. A spokesman said that it was all part of the team's plan to check that the newly redesigned part of the hybrid system fitted for Saturday to replace the one that failed on Thursday was working as hoped. A spokesman said: 'We made a planned stop of the car to confirm the MGU-K re-engineered sealing part installed this morning.' Button has since returned to the track, but the drizzle of late morning limited his running before lunch."
Not everyone takes a break...
Getty ImagesCopyright: Getty Images
F1 journalist Dan Knutson in Barcelona: "Red Bull has a lounge area set up next to the engineers' office on the top of the transporters. But even if it were not a bit too cool for the engineers to be lounging around outside, they have far too much work to do to take a break."
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Anthony Wyatt: You have made a OAP in Bexhill very happy hope bbc is there tomorrow. THANKS.:)
Good news Anthony, we will indeed be back with live text commentary tomorrow.
Summary of the morning session
Max Verstappen tops the timesheet for the morning
Sebastian Vettel spins in the Ferrari early on
Jenson Button's McLaren stops on circuit, returns after 90 mins
Mercedes' Lewis Hamilton completes 41 laps
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The chequered flag is out to signal the end of the morning session. Felipe Massa crosses the line as everyone heads off for a bit of food.
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LotusCopyright: Lotus
Lotus: Scores on the doors at the brink of lunch. We're staying inside whilst it's cold and wet outside.
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Steady progress for Marcus Ericsson as he makes his third trip round the Circuit de Catalunya in the Sauber, but is still to set a timed lap.
He has just Sebastian Vettel for company with the others having gone back in.
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SauberCopyright: Sauber
Felipe Massa heads back in but there is further activity as Marcus Ericsson finally gets out on the circuit after problems with the Sauber this morning. He is joined be Sebastian Vettel and Max Verstappen.
Massa's visit from a mate
Felipe MassaCopyright: Felipe Massa
Felipe Massa has some pretty cool friends. He was joined at the circuit yesterday by Barcelona and Brazil forward Neymar.
"Thanks for coming my bro Neymar you are a great boy," Massa tweeted.
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This will likely be Felipe Massa's last action of the day, with Valtteri Bottas taking over in the afternoon.
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Now then, some activity before the sandwiches are put out for drivers and team staff as Felipe Massa ventures on to the circuit in his Williams.
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How will Verstappen do this season?
Ewan West: If I were Red Bull I'd like to see Verstappen at least match the performances of Kvyat last season.
Diggrich: Verstappen will score points, in my view a couple of times within the top-10, maybe with one or two top seats.
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SauberCopyright: Sauber
It looks like Marcus Ericsson will indeed venture out before lunch. He is getting into his Sauber as we speak...
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PirelliCopyright: Pirelli
Pirelli Motorsport: It's started raining in Barcelona. Just to prove it, here's a photo of some people wearing hats.
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Pastor Maldonado breaks the silence and braves the drizzle to head back out on to the circuit with intermediate tyres on.
It is only a brief foray on the track, though, as he soon heads back in.
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WilliamsCopyright: Williams
Williams: Rain reported on the circuit so Felipe Massa pits. Let's see how long this shower lasts....
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Mercedes: Imagine that? It's now raining... cue flood (*groan*) of damp pit lane snaps...
Lewis Hamilton and Daniil Kvyat were lapping in the 1:26s but with those spots of rain still falling, they are both back in, leaving the track empty with just under 40 minutes until lunch.
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BBCCopyright: BBC
F1 journalist Dan Knutson in Barcelona: "Part of Toro Rosso's pre-season testing programme is aimed at getting rookie drivers Max Verstappen and Carlos Sainz Jr prepared for the season ahead.
"The team are using these orange pylons to give them reference points where to stop when they come into the pits."
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How will Verstappen do this season?
Chris Akrill: Just watched Max [Verstappen] round the track. looking fast, looking good. He's got potential to make it an interesting season. Age won't matter.
Mike Heal: I think Verstappen will do well. Many doubted Kvyat last year and he impressed. Red Bull have a knack of finding great talent.
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MercedesCopyright: Mercedes
Mercedes: Guess who's back? Well, Lewis Hamilton... but also that gosh darn cone! What is this, fresher's week?! ;)
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We were expecting some rain and, while it held off for a while, it looks like it has finally arrived. Mercedes reports that there are a few spots but they are "not significant yet".
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Sauber: 'Fire up'! Marcus is getting ready and we plan to head out for some laps before the lunch break.
Getty ImagesCopyright: Getty Images
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Good news Sauber fans, looks like Marcus Ericsson has been pulled from his driver room and his about to get involved...
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What are your expectations for Max Verstappen in 2015? Is it too much to young or could he produce one of the most impressive performances by a rookie driver?
An improvement from the rookie Max Verstappen as he first goes round in 1:24.739, almost two seconds faster than Lewis Hamilton, currently in second.
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Back to on the circuit matters, and Jenson Button is back out, three laps to the good on his return. Hopefully those earlier troubles are behind McLaren.
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Although it is making me want to do the Nico dance. Mercedes wins?
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MercedesCopyright: Mercedes
The top of my twitter feed has taken a bizarre turn with Mercedes tweeting a 'video' of Nico Rosberg doing the 'Nico Dance'.
Not sure what more you can say about that...
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Daniil Kvyat is back on the circuit and clocks 1:26.589 with his latest effort to move up to fifth fastest. Sebastian Vettel is also out there, with Pastor Maldonado soon joining them. No-one has joined pacesetter Max Verstappen in strapping on soft tyres.
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Chris Akrill: Sat near turn 7 at Catalunya. Ferrari look awesome. Can't understand the commentator, so keep us updated on what's happening elsewhere.
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Toro RossoCopyright: Toro Rosso
Toro Rosso: Barcelona Test - Day 3. Have a look.. Max is on top ;)
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The earlier reported power issues for Jenson Button's McLaren has hampered his mileage this morning, he is the only driver to have been out on circuit to have a single figure lap count, having managed nine.
He pops on to the circuit for an installation lap, but is back in and doesn't look to be out again any time soon.
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Williams F1Copyright: Williams F1
Williams: Pitstop practice in full swing for the team here.
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Fresh from bolting on soft tyres, Max Verstappen is back out on the track...and goes fastest of all as his Toro Rosso is round in 1:25.417s. That has come on his 43rd lap of the morning, the most of any driver out there.
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Edson Charikinya: It will take getting used to seeing Vettel in Ferrari red.
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Getty ImagesCopyright: Getty Images
Just as I sent through that update, Sebastian Vettel posts his fastest lap time of the morning, going round in 1:26.407s to climb into second place. Daniil Kvyat is out once again, and finishes a lap for the first time today, a 1:30.663. He then improves with 1:28.976 to move above Jenson Button into seventh.
Testing day three so far
1. Lewis Hamilton (Mercedes) 1:26.142
2. Felipe Massa (Williams) 1:26.912
3. Max Verstappen (Toro Rosso) 1:27.417
4. Pascal Wehrlein (Force India) 1:27.699
5. Sebastian Vettel (Ferrari) 1:27.823
6. Pastor Maldonado (Lotus) 1:28.257
7. Jenson Button (McLaren) 1:29.151
8. Daniil Kvyat (Red Bull) No time
9. Marcus Ericsson (Sauber) No time
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BBCCopyright: BBC
F1 journalist Dan Knutson in Barcelona: "A rubbish truck is making the rounds in the paddock. On race weekends this is done late in the evening or very early in the morning as Bernie Ecclestone would never allow such a sight to blight his pristine paddock."
Pastor Maldonado heads out to give Lewis Hamilton some company on the circuit.
Still waiting for official confirmation on what happened to Jenson Button, but suggestions are that his McLaren shut down on the track.
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Dennis Axford: Very quiet on the Williams front, just seem to be getting on with it as they did last season.
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Lewis Hamilton is up to 30 laps for the day with his best time 1:26.142. He is on the medium tyre and has been lapping in the 1:36s, but shaves nine seconds off his latest run.
He is the only driver on the circuit as Pascal Wehrlein, who had climbed up to fourth with 1:27.699, pits.
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Toro RossoCopyright: Toro Rosso
Toro Rosso: Barcelona Test - Day 3. Fifty Shades of Grey... but rain holding off for now!
"Was Friday the day Formula 1 finally glimpsed the potential of the 2015 Mercedes? It had been a low-key pre-season until then, but when Lewis Hamilton unleashed a lap only 0.3secs off the pace on tyres that were at least a second a lap slower than those used by everyone ahead of him, it did not take much imagination to work out what that probably meant. And race simulation runs done simultaneously by Hamilton and Red Bull's Daniel Ricciardo only strengthened that impression. Hamilton's average lap time was a whopping 0.816secs quicker than Ricciardo's. They were on different tyre strategies, but that is quite some margin."
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I wonder if Lewis Hamilton has fully shaken off the effects of the illness that kept him out of the car on Thursday? He was well enough to get some time on the circuit yesterday, although conceded he still didn't feel 100%. He remains the pacesetter almost two hours into today's testing.
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Still waiting for Daniil Kvyat to set a lap time this morning. He has been round the circuit 12 times for Red Bull so far, but has made a practice pitstop at the end of each lap.
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Max Verstappen and Sebastian Vettel improve on their benchmark times with laps of 1:27.417 and 1:27.864 respectively.
"No-one is surprised that the Mercedes is showing so much pace. Domination of the level showed by the team last year does not evaporate overnight, and their rivals clearly have a lot of work to do, even if Nico Rosberg tried to play things down on Friday when he said: 'The others have really stepped up their game, the lap times are surprising to us and it seems Ferrari have made the biggest step right now.' He added that Ferrari were 'for sure' a threat, and that Mercedes' 'eyes are definitely wide open at the moment'."
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LotusCopyright: Lotus
Lotus F1: All focused for next run Pastor Maldonado?
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Pascal Wehrlein is the first to head back out after that stop by Jenson Button, quickly followed by Lewis Hamilton, Sebastian Vettel and Max Verstappen.
Despite the early forecast, the weather is holding up for now.
Completed laps
Max Verstappen (Toro Rosso) - 20
Lewis Hamilton (Mercedes) - 18
Felipe Massa (Williams) - 15
Pastor Maldonado (Lotus) - 15
Daniil Kvyat (Red Bull) -12
Sebastian Vettel (Ferrari) - 11
Pascal Wehrlein (Force India) - 9
Jenson Button (McLaren) - 6
Marcus Ericsson (Sauber) - 0
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The circuit is green again after Jenson Button's McLaren was quickly recovered.
"That is not what McLaren wanted - the car stopped by the side of the track less than 90 minutes into the day's running. The team will hope this is not a major issue, and that Jenson Button can be returned to running relatively quickly.
"Another major delay would be a significant setback, and the prospect of it being as failure of the newly redesigned part on the MGU-K that was introduced for today does not bear thinking about."
Testing day three so far
1. Lewis Hamilton (Mercedes): 1:26.142
2. Felipe Massa (Williams): 1:26.912
3. Pastor Maldonado (Lotus): 1:27.257
4. Max Verstappen (Toro Rosso): 1:28.566
5. Sebastian Vettel (Ferrari): 1:29.076
6. Jenson Button (McLaren): 1:29.151
7. Pascal Wehrlein (Force India): 1:35.599
8. Daniil Kvyat (Red Bull): No time
9. Marcus Ericsson (Sauber): No time
Get involved #bbcf1
Simon Nicoll: Fingers crossed for a competitive season with exciting safe racing, several teams looking good in testing, fantastic.
Red flag
Another red flag as Jenson Button brings his McLaren to a halt at the edge of the track at Turn 7...
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Marcus EricssonCopyright: Marcus Ericsson
This tweet from Marcus Ericsson suggests he won't be heading out any time soon.
"I'm not a morning person anyway so that's OK," he tweets. "Give me a shout when we're ready. I'm in my driver room."
Nice socks Marcus...
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Sebastian Vettel has been making up for lost time after this morning's spin with 10 laps to his name now, he has the fifth fastest time - a 1:28.933s.
Daniil Kvyat, who has been practicing pit stops this morning, is the only driver who has been on the circuit this morning yet to clock a timed lap.
"Alonso admitted the team were unlikely to be ready for the first race. 'We will arrive to Australia hoping Australia was in June or July, but it's in March and I don't know if we will arrive completely ready, but we will arrive in the best conditions we can,' the Spaniard said. 'I am happy with the progress we are making.'
"Alonso's overall confidence in the project, though, has not dimmed. 'I don't know how long it will take to win but sooner or later we will do it,' he said."
"Jenson Button is back in the McLaren on Saturday, for what he hopes will be his first proper day's testing of the winter - and the team's for that matter. Fernando Alonso managed 59 laps on Friday, and at a decent-ish lick, but the Honda engine was then carrying a temporary fix to the problem with the hybrid system that had stopped Button on Thursday. That part has now been replaced with a new design, which Honda hopes will fix it for good. But racing director Eric Boullier made it clear how much McLaren had missed out with all the engine problems over the first half of testing, saying they had done '50%' of what they had hoped to do by this stage."
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SauberCopyright: Sauber
No running yet from Sauber. Marcus Ericsson is the man who should be heading out on to the circuit today but at the moment he is having to wait patiently as his team look into addressing a gearbox issue.
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F1 journalist Dan Knutson in Barcelona: "Red Bull has been practicing pit stops this morning, giving Daniil Kvyat and the crew members some training for the season.
"The team did a number of practice stops yesterday with Daniel Ricciardo, changing tyres and also at times changing the steering wheel, and the nose cone and front wing."
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Max Verstappen is up into the third after going round in 1:28.566 for Toro Rosso.
Five drivers have set timed laps so far: 1) Hamilton - 1:26.142 2) Massa 1:27.544 3) Verstappen 1:28.566 4) Button 1:29.151 5) Wehrlein 1:36.599
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Installation lap done, Jenson Button records a 1:29.151s with his first timed effort to go third fastest, behind Felipe Massa and Lewis Hamilton.
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Mike Heal: As a McLaren fan it pains me to say Ferrari have impressed me in testing. Kimi seems much more content. Hope it's another good day us.
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McLaren: JB's install lap complete, so back out in the MP4-30 to lay some more rubber.
"Fernando Alonso described what was effectively McLaren's first proper day of testing with the Honda engine as a 'beautiful day', as well he might when the 59 laps he achieved almost matched the total the team managed over the entire four days of the first test in Jerez earlier this month.
"And considering the car was running with a botched fix on the Honda engine after a hybrid system failure on Thursday, the times weren't bad, either. 'Today finally showed to the team, to all of us, that we are in the right direction,' Alonso said. 'The potential of the car is there, with limitations or not the car feels good, feels quick.'
"Jenson Button is back in the car today, and with what Honda hope will be a definitive fix for the hybrid problem they suffered on Thursday."
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Despite McLaren's struggles on Thursday, they had a much better day yesterday as Fernando Alonso set the sixth-fastest time and completed more than 50 laps after McLaren had cobbled together a fix for the engine problem that hampered Jenson Button.
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Good timing Nick, JB has just rolled out onto the circuit in the McLaren. Button will be hoping for plenty of running this morning having had to call a halt to proceedings after just 21 laps on Thursday.
Sebastian Vettel is back out too for Ferrari after his early venture into the gravel this morning.
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Nick: Any sign of Jenson Button in the McLaren yet?
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John Passman: "I have a feeling it will be a Mercedes again, unless Ferrari really have made a massive leap."
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Lewis Hamilton, on medium tyres, has been steadily improving and sets a new benchmark time of 1:26.142s.
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Max Verstappen and Pascal Wehrlein both clock their first timed efforts - 1:32.195s and 1:36.599s respectively. Verstappen then improves to 1:31.253s.
Get involved #bbcf1
I've just realised I've been rambling away without any input from you good people, so let's stick a question or two out there shall we?
Simple really, who has impressed you the most in testing so far? Do you think this season will be more competitive? Who is your (very early) tip for the title and why?
Let us know via #bbcf1 and, if you are old school, send us a text on 81111 (UK only)
"It was Red Bull's Daniel Ricciardo who grabbed the headlines on Friday, edging out Kimi Raikkonen's Ferrari and Felipe Massa's Williams for fastest time. And perhaps more importantly for Red Bull it was their first day without any major reliability problems. Ricciardo said this was 'better' and that it was 'encouraging to see us in the front group of cars'.
"The Renault engine, too, is an improvement: 'It definitely has some more ponies; we knew it would. it was a question of how much we could close the gap. we're not as fast in the speed traps but we have more to come.'"
Red Bull ready to go
Red Bull RacingCopyright: Red Bull Racing
Red Bull Racing: Thumbs up from Dany. He's good to go for Day Three!
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Lewis Hamilton improves to 1:33.246s before shaving almost three seconds off that time as he continues to rack up the laps early doors.
We're expecting some rain later, so there's a good chance teams will be getting as much running as they can under their belts this morning.
"Was Friday the day Formula 1 finally glimpsed the potential of the 2015 Mercedes?
"It had been a low-key pre-season until then, but when Lewis Hamilton unleashed a lap only 0.3secs off the pace on tyres that were at least a second a lap slower than those used by everyone ahead of him, it did not take much imagination to work out what that probably meant. And race simulation runs done simultaneously by Hamilton and Red Bull's Daniel Ricciardo only strengthened that impression. Hamilton's average lap time was a whopping 0.816secs quicker than Ricciardo's.
"They were on different tyre strategies, but that is quite some margin."
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Lewis Hamilton, who recovered from illness to get some track time under his belt on Friday, had snuck his installation lap in before Sebastian Vettel's spin into the gravel, so he is our first driver to pop a time on the board - 1m33.364s.
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Williams: Install lap done, so Felipe Massa returns to the the garage reporting track conditions are 'Okay' #weareracing
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The track is once again green and cars are streaming out. Lewis Hamilton in his Mercedes, as well as Felipe Massa, Pastor Maldonado, Daniil Kvyat and Pacal Wherlein.
"If Sebastian Vettel has indeed lost control of the Ferrari and dropped it on his first lap out of the pits, he can console himself with the thought that he is not the first great champion to suffer such an embarrassment.
"Those with long memories may recall that Alain Prost spun off on the warm-up lap for the 1991 San Marino Grand Prix. Vettel might not want to recall what happened later that season, though. Prost was sacked for making critical comments about the car."
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F1 journalist Dan Knutson in Barcelona: "After two sunny days, a front has moved in on the Circuit De Barcelona-Catalunya and rain is forecast for later in the day.
"The air temperature is 6.8C and the track temperature was 9.4C when the green light at the end of the pit lane signalled the start of the day."
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Sebastian Vettel's stranded Ferrari has been lifted onto the recovery truck and the circuit is clear. Take two...
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Mercedes: Scratch that - red flags out almost instantly. Lewis Hamilton back at base reporting a rather slippery surface.
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MercedesCopyright: Mercedes
Mercedes: "It's green light and away we go! Lewis Hamilton at the wheel today... let's do this!"
"Oops. Not a good start to the day for Sebastian Vettel, who has taken over the Ferrari from Kimi Raikkonen for the final two days of the test. The four-time champion has gone off into the gravel on his out lap. The cause of the incident is unclear for now, but it appears as if the German may have lost the car approaching Turn Five and simply spun."
Red flag
...and is in the gravel at Turn 5. Looks like he spun off. He is out of his car and out comes the red flag.
Go! Go! Go!
The circuit is open and no messing about from Sebastian Vettel, he is straight out for Ferrari...
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F1 journalist Dan Knutson: "After two sunny days, a front has moved in on the Circuit De Barcelona-Catalunya and rain is forecast for later in the day. The air temperature is 6.8C and the track temperature is 9.4C as the green light at the end of the pit lane signals the start of the day."
"Half-distance in the team's preparations for Formula 1 has passed, and there are only six days left before the cars finish pre-season testing and are packed up and then sent to Australia for the first race of the season.
"So far, testing has been intriguing. Ferrari appear to have made a genuine step forward, Williams and Red Bull will be in the mix, and McLaren-Honda look as if they might just finally be extricating themselves from the mire of unreliability that afflicted their first five days of 2015. But Mercedes, clearly and obviously, remain the team to beat.
"Will those impressions be changed over the forthcoming six days, starting this morning at the demanding Circuit De Barcelona-Catalunya?"
The clock is ticking
Getty ImagesCopyright: Getty Images
Twenty one days and 21 hours; 31,500 minutes; 1,890,000 seconds. Whichever way you look at it, the first race of the 2015 Formula 1 season is fast approaching.
Just over three weeks until lights out at the Australian GP, and we have just passed the halfway mark in pre-season testing.
Is the reigning champion looking in good shape? Who could be his biggest challengers? All that and more could become clearer this weekend...
Live Reporting
Gary Rose
All times stated are UK
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Getty ImagesCopyright: Getty Images - Max Verstappen tops the timesheet for the morning
- Sebastian Vettel spins in the Ferrari early on
- Jenson Button's McLaren stops on circuit, returns after 90 mins
- Mercedes' Lewis Hamilton completes 41 laps
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Latest PostPost update
It certainly makes things interesting for tomorrow. Can McLaren sort things out and get some decent running in on the final day of testing? Join me at 08:00 GMT tomorrow to find out.
I'll leave you with Andrew Benson's report, and until tomorrow, good bye.
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In total for testing McLaren have managed less than 200 laps. Every other team has managed well over 400, with Mercedes leading the way with over 800. Worrying times for McLaren?
Day three testing times in full
1 Pastor Maldonado (Ven) Lotus-Mercedes 1:24.348
2 Max Verstappen (Ned) Toro Rosso-Renault 1:24.739
3 Lewis Hamilton (GB) Mercedes 1:26.142
4 Marcus Ericsson (Swe) Sauber-Ferrari 1:26.340
5 Sebastian Vettel (Ger) Ferrari 1:26.407
6 Daniil Kvyat (Rus) Red Bull-Renault 1:26.589
7 Felipe Massa (Brz) Williams-Mercedes 1:26.912
8 Pascal Wehrlein (Ger) Force India-Mercedes 1:27.333*
9 Valtteri Bottas (Fin) Williams-Mercedes 1:27.556
10 Jenson Button (GB) McLaren-Honda 1:29.151
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Mercedes: Job done! 101 the total for Lewis Hamilton today - he's powered through these past couple of sessions!
Chequered flag
Out comes the chequered flag to bring day three to a close. Five drivers got over 100 laps under their belt, a figure Jenson Button can only look on enviously at after a frustrating day for McLaren.
Pastor Maldonado finishes fastest for the day.
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Mercedes: That's his century! 100 laps hit for Lewis Hamilton Howzaaaat! ;)
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Jenson Button completes a lap, heads in, heads back out but soon heads back in again.
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That's better, a 1:27.556 is almost two seconds quicker than Jenson Button's best effort, so Valtteri Bottas is up into ninth.
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Ah, a late timed lap for Valterri Bottas but it is not enough to lift him off the bottom of the timesheet as he clocks 1:38.067.
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Williams: Final 10 minutes and Valtteri Bottas heads out with a clear visor as the light fades.
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Sauber: One more run on the soft tyres.
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Jenson Button heads out, he'd certainly welcome a few trouble-free laps, and he is quickly followed by Marcus Ericsson, Valtteri Bottas and then Pascal Wehrlein.
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The green flag is waved and 10 minutes remain for teams to rattle up a few late laps.
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Force India: Red flag halts proceedings. It may be a bit of a scramble for the pit lane once the session goes green again! Every lap counts.
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It was the Toro Rosso that brought out the red flag and the recovery truck trundles over to lift Max Verstappen's car. Should be enough time to squeeze in a few more laps before day three of testing comes to an end.
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Max Verstappen stopped just before Turn 1, while Jenson Button also came to a halt at the pit exit.
Red flag
McLaren head back out, but there is a red flag...
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A bit more activity on the circuit as we enter the final 30 minutes with Sebastian Vettel increasing his lap total for the day in the Ferrari. Pascal Wehrlein, in the Force India, and Toro Rosso's Max Verstappen are also out there.
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Force India: Pascal's tally is up to 77 laps, a very good haul for the youngster who has been through a plan of setup work and longer runs. The crew has completed some routine checks after the latest long run, so we're ready to put in some extra laps before the end!
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Daniil Kvyat pops out in the Red Bull but is straight back in and once again the circuit is empty. Sensing there is little more to see today, spectators are starting to make their way home.
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Pastor Maldonado cuts a lonely figure as he weaves his way around the circuit in the Lotus - the only car on the circuit.
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Just over 45 minutes remaining of testing for today, will we see another appearance by the McLaren? Yes, is the answer, as Jenson Button ventures out but how many more laps can he add to the 18 he has completed today?
Completed laps on day three
1. Max Verstappen 125
2. Daniil Kvyat 102
3. Sebastian Vettel 101
4. Pastor Maldonado 94
5. Lewis Hamilton 86
6. Pascal Wehrlein 76
7. Felipe Massa 55
8. Marcus Ericsson 46
9. Valtteri Bottas 36
10. Jenson Button 18
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Nothing much going on on the circuit at the moment, with Max Verstappen and Valtteri Bottas performing pit-stop practices. Sebastian Vettel continues to increase his mileage on the circuit as he surpasses 100 laps for the day in the Ferrari.
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Tony Dickinson: Maybe this is a secret plan by McLaren to lull everyone into a false sense of security.
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Marcus Ericsson, on the soft tyres, is up to fourth with 1:26.340, and the times from third fastest to seventh fastest are separated by nine tenths of a second.
Ericsson, Max Verstappen, and Pascal Wehrlein are the drivers on the track at the moment.
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F1 journalist Dan Knutson in Barcelona: "Williams did the same thing last year - doing pit stop after pit stop with the driver coming in after each lap and therefore never setting a lap time. Valtteri Bottas has now done 34 laps doing just that. It's expected that he will do some proper timed runs before the session ends."
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Brief. Jenson Button is once again back in the pits after lap 18.
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A limited-power McLaren is guided back on to the circuit by Jenson Button.
Meanwhile, Daniil Kvyat has surpassed 100 laps for the day as he heads off on number 103. Only Max Verstappen, on 115, has managed more today.
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Sauber: Pit-stop practice. Marcus Ericsson is now in the garage and gives feedback.
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Andrew Benson
Chief F1 writer
"More on McLaren's problems. It turns out our earlier suspicions were right - McLaren's delays have been caused by the same part that stopped Jenson Button on Thursday, a seal on the motor generator unit that recovers energy from the rear axle (the MGU-K). A new design was fitted to the car for today's running and Honda hoped that would fix the problem. But it has not.
"A spokeswoman said: 'After the morning session, the car fed back MGU-K issues similar to what we experienced on Thursday, so we brought it back to the garage. After a thorough check, we have decided to resume testing with limited power to the MGU-K. A new re-engineered seal is scheduled to arrive and will be applied later this evening.'"
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It looks like it is a short stay back in the garage for Jenson Button, with the McLaren seemingly set to re-enter the fray. Meanwhile, Lewis Hamilton is back on the circuit, currently lapping in the 1:26s.
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Mark Snow: Hope McLaren have not scooped the 'F12015 sunk without trace award' again before the season's even got under way.
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Valtteri Bottas is up to 30 laps without setting a time as Jenson Button heads back in at the end of lap 15.
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Jenson Button completes his 14th lap of the day and stays out on the circuit. All being well, he will have 90 minutes out there to rack up the mileage.
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...and out goes Jenson Button, his first trip on to the circuit since this morning.
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Daniil Kvyat on his race simulation, pits for softs with 12 laps to go. Meanwhile, it seems like there may indeed be some activity in the McLaren garage...
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Andrew Benson
Chief F1 writer
"McLaren say they hope to have Jenson Button out again 'very soon'. The team said that 'there were a number of things we had to check and some issues we had to address, which took some time'. They promise more details shortly."
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No sign of the McLaren on the circuit yet, so here's a picture of a beaming Fernando Alonso stood behind the iconic McLaren MP4/4 from the 1988 season.
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Lewis Hamilton completes an 11-lap stint on medium tyres, with the majority of those laps either 1:27s or 1:28s.
Sebastian Vettel also completes a flurry of laps, heading in after his 16th in succession with those averaging in the 1:29s. He is closing in on a century of laps for the day and it is looking like being another pleasing outing on the circuit for Ferrari, despite his spin right at the start of the day.
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Valtteri Bottas has yet to clock a timed lap, despite managing 22 laps. He has spent the afternoon doing some pit-stop practice.
Testing day three update (as of 15:15 GMT)
1. Pastor Maldonado (Lotus) 1:24.348 (63 laps)
2. Max Verstappen (Toro Rosso) 1:24.739 (97 laps)
3. Lewis Hamilton (Mercedes) 1:26.142 (72 laps)
4. Sebastian Vettel (Ferrari) 1:26.407 (92 laps)
5. Daniil Kvyat (Red Bull) 1:26.589 (81 laps)
6. Felipe Massa (Williams) 1:26.912 (55 laps)
7. Pascal Wehrlein (Force India) 1:27.333 (57 laps)
8. Marcus Ericsson (Sauber) 1:28.858 (32 laps)
9. Jenson Button (McLaren) 1:29.151 (12 laps)
10. Valtteri Bottas (Williams) No time (22 laps)
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Jenson Button will no doubt be itching to get back out on the circuit. He has now dropped to the bottom of the timesheet as Marcus Ericsson clocks 1:28.858 to move up to eighth. He heads back in, leaving Lewis Hamilton, Sebastian Vettel and Daniil Kvyat on track.
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Sauber: Marcus Ericsson is now on a run with medium tyres.
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Mercedes: UPDATE: 2hrs of HAMmertime remain this week - 66 laps on the board for Lewis Hamilton so far: he's on track now...
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Lewis Hamilton heads back out on the medium compound and improves on his best time from the morning with a 1:26.076. He remains third fastest, though, with Pastor Maldonado and Max Verstappen out in front.
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Williams: More pitstops...This time the boys prepare for Valtteri Bottas to hit his marks.
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F1 journalist Dan Knutson in Barcelona: "After a stint in the garage, Daniil Kvyat has resumed his race simulation, which had 32 laps to run. He has the medium compound Pirelli slicks on his Red Bull."
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Jenson Button's lack of activity means he has completed just 12 laps on the third day of testing so far.
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Andrew Benson
Chief F1 writer
"There has still been no sign of the McLaren-Honda this afternoon, and that is not good news for the team. Jenson Button has done only 12 laps so far and although the team said earlier that the stoppage Button suffered this morning was 'planned', one has to assume something else is wrong, because McLaren need nothing more than mileage at the moment. We're trying to find out what's going on."
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Lewis Hamilton pits after some mid-distance runs on the medium tyre and, at the moment, there is just Max Verstappen out on track. The rookie driver's best of the day - a 1:24.739 - keeps him in second.
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Marcus Ericsson, on the medium tyre, clocks his best of the day, a 1:29.171 but it is just shy of Jenson Button's fastest and he remains bottom of the timesheet.
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F1 journalist Dan Knutson in Barcelona: "With 32 laps to go in his race simulation, Daniil Kvyat pitted and the mechanics pushed the car into the garage.
"Prior to that the mechanics had been doing a race simulation of their own and sitting on chairs in the garage. But unlike a race weekend there was no TV coverage to watch."
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Richard Clist: Have McLaren quit for the day.
We're looking into the situation at McLaren, Richard, hopefully we will be able to update you soon.
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After a breather in the Lotus garage, Pastor Maldonado heads back out and he is quick, fastest of all through the first sector and...it's the fastest lap of the day - 1:24.348 on super softs.
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Frank Lopez: That size zero is yielding zero test results. Have McLaren shot themselves in the foot overcomplicating the car?
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Lewis Hamilton and Sebastian Vettel are racking up the laps, the former lapping in the 1:28s with Vettel averaging around two seconds slower. Meanwhile, Daniil Kvyat ends his long run by returning to the Red Bull garage.
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Pastor Maldonado improves again, joining pacesetter Max Verstappen in dipping below 1:25s as he clocks 1:24.917.
Valtteri Bottas, meanwhile, has six laps to his name but is yet to set a time and interestingly, no sign of Jenson Button in the McLaren on the circuit this afternoon...
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With just under three hours left, here's an update on fastest laps and completed laps, courtesy of Lotus.
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Lotus: Must be tiring work in the car for Pastor Maldonado - time for a quick pitlane siesta.
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Daniil Kvyat completes the 25th lap of his race simulation, 40 more to go. He is lapping in and around the 1:31 mark.
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Mercedes: And the selfie king returns to the track! Sun out, medium tyres on, action!
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Lewis Hamilton has put away his camera and is out on the circuit for the first time this afternoon, medium tyres bolted on.
Pastor Maldonado, meanwhile, clocks 1:26.208 - the third fastest time of the day as Valtteri Bottas heads out for Williams. He has replaced Felipe Massa, with the two sharing testing duties today.
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Anthony Wyatt: "RE: 13:45 a political bluff or just training? It's so interesting. a game of chess, but more colours."
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F1 journalist Dan Knutson in Barcelona: "It's amusing to see that Force India has sight screens up at its garage door [see 13:45 entry]. That's the 2014 car, so the team really has no technical things to conceal. Perhaps they are just hiding that ugly anteater nose on the car."
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Fed up with the cold and wet weather in the UK this week? At least it is not too great over in Spain as well.
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Ten laps into his race run, Daniil Kvyat pits for mediums, heads back out and dips under 1:30, clocking 1:29.7 on the new tyres.
Sebastian Vettel is out, but only briefly as he heads back into the pits after completing a couple of laps.
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You may have been wondering where Lewis Hamilton is this afternoon. He is still in the Mercedes garage, posing for a selfie.
He tweeted: "Hope you're having a great day! Still feeling under the weather but I'm pushing for you guys."
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The sun is breaking through the clouds, prompting one or two teams to start getting things ready for a venture on to the circuit, Pascal Wehrlein one of those as his Force India rolls out of the garage.
The laps are ticking down on Daniil Kvyat's race simulation, too, with 'L61' on the Red Bull board. He has been lapping in the 1:30 and 1:31s.
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Force India: Still quiet in the garage as we wait for the track conditions to improve...
There's a conspicuous addition of a driver to the car, though, so some more lappage could be on the cards soon.
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F1 journalist Dan Knutson in Barcelona: "Red Bull is doing a very thorough race simulation. A crew member placed bottles of water at each of the seven seats on the pit wall where Christian Horner, Adrian Newey and the engineers sit (although they are not all out there now.)
"Daniil Kvyat did one lap and then came into the pits, stopped 50 yards away from the Red Bull garage, and shut the engine off. The mechanics then pushed the car to the garage, just as it would be pushed from the back of the grid to its starting slot on the grid.
"After a waiting period similar to what it would be on the grid before the start of the race, Kvyat then headed out with intermediate rain tyres fitted to the car, did one lap and pitted for a set of the soft compound Pirelli tyres. He is now off and running and doing the race sim."
Post update
This morning's pitstop practice is put to good use as Daniil Kvyat pits for softs and heads back out to begin his race simulation.
Marcus Ericsson, meanwhile, is doing his best to make up for lost time with eight laps to his name so far, the best a 1:42.179.
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Mercedes: A brief exploratory foray around the circuit only for Lewis Hamilton so far following the lunch break. It's a little greasy out there...
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Marcus Ericsson is out for a cautious venture around the track, checking the conditions. Daniil Kvyat is back out too.
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Sauber: Lunch break is over. Marcus (Ericsson) is going out on intermediates as the track still seems to be damp.
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It is an exploratory lap for Daniil Kvyat on inter tyres as he heads back in and is wheeled back to the Red Bull garage.
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Everyone is briefly back in the pits, before Daniil Kvyat decides to head on to the empty circuit. He completed 34 laps this morning, spending most of his morning making practice pitstops.
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F1 journalist Dan Knutson in Barcelona: "Red Bull has a pit board with L65 on it ready to go. A race distance here is 66 laps, so it looks like Daniil Kvyat will be doing a race simulation soon."
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Pascal Wehrlein takes the Force India out on to the circuit for the first time in the afternoon session, joining Lewis Hamilton and Max Verstappen, who is on the medium tyre.
It appears some of the teams are waiting for the circuit to dry up a bit before heading out, with some areas still a little damp.
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The reigning world champion was able to gulp down a brew during lunch. He seems to be back on form after a bout of illness earlier this week.
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Lewis Hamilton is joined on the circuit by this morning's pacesetter Max Verstappen, who got plenty of mileage in before lunch.
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McLaren: The iconic MP4/4 joins us in the garage today. Looks stunning despite the grey Barcelona skies.
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Lewis Hamilton also heads out on to the circuit as Pastor Maldonado's brief foray comes to an end.
Grey skies above the circuit, and only a few spots of rain falling.
Go! Go! Go!
Right then, thanks for sticking with me over lunch and for those of you who have returned or just joined, welcome!
The afternoon session is live and out goes Pastor Maldonado.
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Romain Grosjean: Preparing tomorrow's running with my engineers. Looking sunny
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This is Ferrari's view on how the morning went: "Sebastian went off the track at Turn 5 on his first out-lap, but no damage was done. After that, he went on to complete 46 laps over the course of the morning, the quickest in a time of 1.26:407, third fastest overall.
"Today's programme again features aerodynamic and set-up work. As the rain intensified, the team decided to slightly modify the programme, with normal work set to resume once it's over."
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Here's a couple of shots from this morning to enjoy over your lunch.
This is Sebastian Vettel's Ferrari being recovered after an early spin...
...it was a busy morning for the Red Bull crew as Daniil Kvyat made a number of practice pitstops...
...Kvyat had flow-vis paint on the back of his helmet at one point as the team looked to see where air flowed around the helmet...
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After spinning off the cold track early on, it has been so far so good for Sebastian Vettel and Ferrari.
The new car has been impressive in winter testing, surely we are likely to see Ferrari team principal Maurizio Arrivabene running barefooted at some point in this season?
"I am not so crazy as to change the objectives now," Arrivabene said of the team's low-key objectives.
"Winning two races will be fine. Three will be perfect. Four and I run 100km without shoes to the Maranello hills."
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Force India: Activity is not just in the garage - Sergio Perez sits in dramatic light when interviewed by NBC Sports.
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Good news then, with McLaren's stop this morning not related to any problems with the car itself.
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Andrew Benson
Chief F1 writer
"McLaren have revealed why Jenson Button stopped out on track early in the morning's session. A spokesman said that it was all part of the team's plan to check that the newly redesigned part of the hybrid system fitted for Saturday to replace the one that failed on Thursday was working as hoped. A spokesman said: 'We made a planned stop of the car to confirm the MGU-K re-engineered sealing part installed this morning.' Button has since returned to the track, but the drizzle of late morning limited his running before lunch."
Not everyone takes a break...
F1 journalist Dan Knutson in Barcelona: "Red Bull has a lounge area set up next to the engineers' office on the top of the transporters. But even if it were not a bit too cool for the engineers to be lounging around outside, they have far too much work to do to take a break."
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Get involved #bbcf1
Anthony Wyatt: You have made a OAP in Bexhill very happy hope bbc is there tomorrow. THANKS.:)
Good news Anthony, we will indeed be back with live text commentary tomorrow.
Summary of the morning session
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The chequered flag is out to signal the end of the morning session. Felipe Massa crosses the line as everyone heads off for a bit of food.
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Lotus: Scores on the doors at the brink of lunch. We're staying inside whilst it's cold and wet outside.
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Steady progress for Marcus Ericsson as he makes his third trip round the Circuit de Catalunya in the Sauber, but is still to set a timed lap.
He has just Sebastian Vettel for company with the others having gone back in.
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Felipe Massa heads back in but there is further activity as Marcus Ericsson finally gets out on the circuit after problems with the Sauber this morning. He is joined be Sebastian Vettel and Max Verstappen.
Massa's visit from a mate
Felipe Massa has some pretty cool friends. He was joined at the circuit yesterday by Barcelona and Brazil forward Neymar.
"Thanks for coming my bro Neymar you are a great boy," Massa tweeted.
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This will likely be Felipe Massa's last action of the day, with Valtteri Bottas taking over in the afternoon.
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Now then, some activity before the sandwiches are put out for drivers and team staff as Felipe Massa ventures on to the circuit in his Williams.
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How will Verstappen do this season?
Ewan West: If I were Red Bull I'd like to see Verstappen at least match the performances of Kvyat last season.
Diggrich: Verstappen will score points, in my view a couple of times within the top-10, maybe with one or two top seats.
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It looks like Marcus Ericsson will indeed venture out before lunch. He is getting into his Sauber as we speak...
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Pirelli Motorsport: It's started raining in Barcelona. Just to prove it, here's a photo of some people wearing hats.
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Pastor Maldonado breaks the silence and braves the drizzle to head back out on to the circuit with intermediate tyres on.
It is only a brief foray on the track, though, as he soon heads back in.
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Williams: Rain reported on the circuit so Felipe Massa pits. Let's see how long this shower lasts....
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Mercedes: Imagine that? It's now raining... cue flood (*groan*) of damp pit lane snaps...
Testing day three update (as of 11:25 GMT)
1. Max Verstappen (Toro Rosso) 1:24.739 (55 laps)
2. Lewis Hamilton (Mercedes) 1:26.142 (35 laps)
3. Sebastian Vettel (Ferrari) 1:26.407 (41 laps)
4. Daniil Kvyat (Red Bull) 1:26.589 (31 laps)
5. Felipe Massa (Williams) 1:26.912 (40 laps)
6. Pascal Wehrlein (Force India) 1:27.699 (36 laps)
7. Pastor Maldonado (Lotus) 1:28.966 (41 laps)
8. Jenson Button (McLaren) 1:29.151 (11 laps)
9. Marcus Ericsson (Sauber) No time (0 laps)
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Lewis Hamilton and Daniil Kvyat were lapping in the 1:26s but with those spots of rain still falling, they are both back in, leaving the track empty with just under 40 minutes until lunch.
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F1 journalist Dan Knutson in Barcelona: "Part of Toro Rosso's pre-season testing programme is aimed at getting rookie drivers Max Verstappen and Carlos Sainz Jr prepared for the season ahead.
"The team are using these orange pylons to give them reference points where to stop when they come into the pits."
Get involved #bbcf1
How will Verstappen do this season?
Chris Akrill: Just watched Max [Verstappen] round the track. looking fast, looking good. He's got potential to make it an interesting season. Age won't matter.
Mike Heal: I think Verstappen will do well. Many doubted Kvyat last year and he impressed. Red Bull have a knack of finding great talent.
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Mercedes: Guess who's back? Well, Lewis Hamilton... but also that gosh darn cone! What is this, fresher's week?! ;)
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We were expecting some rain and, while it held off for a while, it looks like it has finally arrived. Mercedes reports that there are a few spots but they are "not significant yet".
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Sauber: 'Fire up'! Marcus is getting ready and we plan to head out for some laps before the lunch break.
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Good news Sauber fans, looks like Marcus Ericsson has been pulled from his driver room and his about to get involved...
Get involved #bbcf1
What are your expectations for Max Verstappen in 2015? Is it too much to young or could he produce one of the most impressive performances by a rookie driver?
Let us know via #bbcf1 or text to 81111 (UK only)
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An improvement from the rookie Max Verstappen as he first goes round in 1:24.739, almost two seconds faster than Lewis Hamilton, currently in second.
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Back to on the circuit matters, and Jenson Button is back out, three laps to the good on his return. Hopefully those earlier troubles are behind McLaren.
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Although it is making me want to do the Nico dance. Mercedes wins?
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The top of my twitter feed has taken a bizarre turn with Mercedes tweeting a 'video' of Nico Rosberg doing the 'Nico Dance'.
Not sure what more you can say about that...
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Daniil Kvyat is back on the circuit and clocks 1:26.589 with his latest effort to move up to fifth fastest. Sebastian Vettel is also out there, with Pastor Maldonado soon joining them. No-one has joined pacesetter Max Verstappen in strapping on soft tyres.
Get involved #bbcf1
Chris Akrill: Sat near turn 7 at Catalunya. Ferrari look awesome. Can't understand the commentator, so keep us updated on what's happening elsewhere.
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Toro Rosso: Barcelona Test - Day 3. Have a look.. Max is on top ;)
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The earlier reported power issues for Jenson Button's McLaren has hampered his mileage this morning, he is the only driver to have been out on circuit to have a single figure lap count, having managed nine.
He pops on to the circuit for an installation lap, but is back in and doesn't look to be out again any time soon.
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Williams: Pitstop practice in full swing for the team here.
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Fresh from bolting on soft tyres, Max Verstappen is back out on the track...and goes fastest of all as his Toro Rosso is round in 1:25.417s. That has come on his 43rd lap of the morning, the most of any driver out there.
Get involved #bbcf1
Edson Charikinya: It will take getting used to seeing Vettel in Ferrari red.
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Just as I sent through that update, Sebastian Vettel posts his fastest lap time of the morning, going round in 1:26.407s to climb into second place. Daniil Kvyat is out once again, and finishes a lap for the first time today, a 1:30.663. He then improves with 1:28.976 to move above Jenson Button into seventh.
Testing day three so far
1. Lewis Hamilton (Mercedes) 1:26.142
2. Felipe Massa (Williams) 1:26.912
3. Max Verstappen (Toro Rosso) 1:27.417
4. Pascal Wehrlein (Force India) 1:27.699
5. Sebastian Vettel (Ferrari) 1:27.823
6. Pastor Maldonado (Lotus) 1:28.257
7. Jenson Button (McLaren) 1:29.151
8. Daniil Kvyat (Red Bull) No time
9. Marcus Ericsson (Sauber) No time
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F1 journalist Dan Knutson in Barcelona: "A rubbish truck is making the rounds in the paddock. On race weekends this is done late in the evening or very early in the morning as Bernie Ecclestone would never allow such a sight to blight his pristine paddock."
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Sauber: Busy times in the media centre.
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Pastor Maldonado heads out to give Lewis Hamilton some company on the circuit.
Still waiting for official confirmation on what happened to Jenson Button, but suggestions are that his McLaren shut down on the track.
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Dennis Axford: Very quiet on the Williams front, just seem to be getting on with it as they did last season.
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Lewis Hamilton is up to 30 laps for the day with his best time 1:26.142. He is on the medium tyre and has been lapping in the 1:36s, but shaves nine seconds off his latest run.
He is the only driver on the circuit as Pascal Wehrlein, who had climbed up to fourth with 1:27.699, pits.
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Toro Rosso: Barcelona Test - Day 3. Fifty Shades of Grey... but rain holding off for now!
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Andrew Benson
Chief F1 writer
"Was Friday the day Formula 1 finally glimpsed the potential of the 2015 Mercedes? It had been a low-key pre-season until then, but when Lewis Hamilton unleashed a lap only 0.3secs off the pace on tyres that were at least a second a lap slower than those used by everyone ahead of him, it did not take much imagination to work out what that probably meant. And race simulation runs done simultaneously by Hamilton and Red Bull's Daniel Ricciardo only strengthened that impression. Hamilton's average lap time was a whopping 0.816secs quicker than Ricciardo's. They were on different tyre strategies, but that is quite some margin."
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I wonder if Lewis Hamilton has fully shaken off the effects of the illness that kept him out of the car on Thursday? He was well enough to get some time on the circuit yesterday, although conceded he still didn't feel 100%. He remains the pacesetter almost two hours into today's testing.
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Still waiting for Daniil Kvyat to set a lap time this morning. He has been round the circuit 12 times for Red Bull so far, but has made a practice pitstop at the end of each lap.
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Max Verstappen and Sebastian Vettel improve on their benchmark times with laps of 1:27.417 and 1:27.864 respectively.
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Andrew Benson
Chief F1 writer
"No-one is surprised that the Mercedes is showing so much pace. Domination of the level showed by the team last year does not evaporate overnight, and their rivals clearly have a lot of work to do, even if Nico Rosberg tried to play things down on Friday when he said: 'The others have really stepped up their game, the lap times are surprising to us and it seems Ferrari have made the biggest step right now.' He added that Ferrari were 'for sure' a threat, and that Mercedes' 'eyes are definitely wide open at the moment'."
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Lotus F1: All focused for next run Pastor Maldonado?
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Pascal Wehrlein is the first to head back out after that stop by Jenson Button, quickly followed by Lewis Hamilton, Sebastian Vettel and Max Verstappen.
Despite the early forecast, the weather is holding up for now.
Completed laps
Max Verstappen (Toro Rosso) - 20
Lewis Hamilton (Mercedes) - 18
Felipe Massa (Williams) - 15
Pastor Maldonado (Lotus) - 15
Daniil Kvyat (Red Bull) -12
Sebastian Vettel (Ferrari) - 11
Pascal Wehrlein (Force India) - 9
Jenson Button (McLaren) - 6
Marcus Ericsson (Sauber) - 0
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The circuit is green again after Jenson Button's McLaren was quickly recovered.
A worry for McLaren?
Andrew Benson
Chief F1 writer
"That is not what McLaren wanted - the car stopped by the side of the track less than 90 minutes into the day's running. The team will hope this is not a major issue, and that Jenson Button can be returned to running relatively quickly.
"Another major delay would be a significant setback, and the prospect of it being as failure of the newly redesigned part on the MGU-K that was introduced for today does not bear thinking about."
Testing day three so far
1. Lewis Hamilton (Mercedes): 1:26.142
2. Felipe Massa (Williams): 1:26.912
3. Pastor Maldonado (Lotus): 1:27.257
4. Max Verstappen (Toro Rosso): 1:28.566
5. Sebastian Vettel (Ferrari): 1:29.076
6. Jenson Button (McLaren): 1:29.151
7. Pascal Wehrlein (Force India): 1:35.599
8. Daniil Kvyat (Red Bull): No time
9. Marcus Ericsson (Sauber): No time
Get involved #bbcf1
Simon Nicoll: Fingers crossed for a competitive season with exciting safe racing, several teams looking good in testing, fantastic.
Red flag
Another red flag as Jenson Button brings his McLaren to a halt at the edge of the track at Turn 7...
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This tweet from Marcus Ericsson suggests he won't be heading out any time soon.
"I'm not a morning person anyway so that's OK," he tweets. "Give me a shout when we're ready. I'm in my driver room."
Nice socks Marcus...
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Sebastian Vettel has been making up for lost time after this morning's spin with 10 laps to his name now, he has the fifth fastest time - a 1:28.933s.
Daniil Kvyat, who has been practicing pit stops this morning, is the only driver who has been on the circuit this morning yet to clock a timed lap.
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Andrew Benson
Chief F1 writer
"Alonso admitted the team were unlikely to be ready for the first race. 'We will arrive to Australia hoping Australia was in June or July, but it's in March and I don't know if we will arrive completely ready, but we will arrive in the best conditions we can,' the Spaniard said. 'I am happy with the progress we are making.'
"Alonso's overall confidence in the project, though, has not dimmed. 'I don't know how long it will take to win but sooner or later we will do it,' he said."
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Andrew Benson
Chief F1 writer
"Jenson Button is back in the McLaren on Saturday, for what he hopes will be his first proper day's testing of the winter - and the team's for that matter. Fernando Alonso managed 59 laps on Friday, and at a decent-ish lick, but the Honda engine was then carrying a temporary fix to the problem with the hybrid system that had stopped Button on Thursday. That part has now been replaced with a new design, which Honda hopes will fix it for good. But racing director Eric Boullier made it clear how much McLaren had missed out with all the engine problems over the first half of testing, saying they had done '50%' of what they had hoped to do by this stage."
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No running yet from Sauber. Marcus Ericsson is the man who should be heading out on to the circuit today but at the moment he is having to wait patiently as his team look into addressing a gearbox issue.
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F1 journalist Dan Knutson in Barcelona: "Red Bull has been practicing pit stops this morning, giving Daniil Kvyat and the crew members some training for the season.
"The team did a number of practice stops yesterday with Daniel Ricciardo, changing tyres and also at times changing the steering wheel, and the nose cone and front wing."
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Max Verstappen is up into the third after going round in 1:28.566 for Toro Rosso.
Five drivers have set timed laps so far: 1) Hamilton - 1:26.142 2) Massa 1:27.544 3) Verstappen 1:28.566 4) Button 1:29.151 5) Wehrlein 1:36.599
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Installation lap done, Jenson Button records a 1:29.151s with his first timed effort to go third fastest, behind Felipe Massa and Lewis Hamilton.
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Mike Heal: As a McLaren fan it pains me to say Ferrari have impressed me in testing. Kimi seems much more content. Hope it's another good day us.
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McLaren: JB's install lap complete, so back out in the MP4-30 to lay some more rubber.
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Andrew Benson
Chief F1 writer
"Fernando Alonso described what was effectively McLaren's first proper day of testing with the Honda engine as a 'beautiful day', as well he might when the 59 laps he achieved almost matched the total the team managed over the entire four days of the first test in Jerez earlier this month.
"And considering the car was running with a botched fix on the Honda engine after a hybrid system failure on Thursday, the times weren't bad, either. 'Today finally showed to the team, to all of us, that we are in the right direction,' Alonso said. 'The potential of the car is there, with limitations or not the car feels good, feels quick.'
"Jenson Button is back in the car today, and with what Honda hope will be a definitive fix for the hybrid problem they suffered on Thursday."
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Despite McLaren's struggles on Thursday, they had a much better day yesterday as Fernando Alonso set the sixth-fastest time and completed more than 50 laps after McLaren had cobbled together a fix for the engine problem that hampered Jenson Button.
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Good timing Nick, JB has just rolled out onto the circuit in the McLaren. Button will be hoping for plenty of running this morning having had to call a halt to proceedings after just 21 laps on Thursday.
Sebastian Vettel is back out too for Ferrari after his early venture into the gravel this morning.
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Nick: Any sign of Jenson Button in the McLaren yet?
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John Passman: "I have a feeling it will be a Mercedes again, unless Ferrari really have made a massive leap."
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Lewis Hamilton, on medium tyres, has been steadily improving and sets a new benchmark time of 1:26.142s.
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Max Verstappen and Pascal Wehrlein both clock their first timed efforts - 1:32.195s and 1:36.599s respectively. Verstappen then improves to 1:31.253s.
Get involved #bbcf1
I've just realised I've been rambling away without any input from you good people, so let's stick a question or two out there shall we?
Simple really, who has impressed you the most in testing so far? Do you think this season will be more competitive? Who is your (very early) tip for the title and why?
Let us know via #bbcf1 and, if you are old school, send us a text on 81111 (UK only)
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Andrew Benson
Chief F1 writer
"It was Red Bull's Daniel Ricciardo who grabbed the headlines on Friday, edging out Kimi Raikkonen's Ferrari and Felipe Massa's Williams for fastest time. And perhaps more importantly for Red Bull it was their first day without any major reliability problems. Ricciardo said this was 'better' and that it was 'encouraging to see us in the front group of cars'.
"The Renault engine, too, is an improvement: 'It definitely has some more ponies; we knew it would. it was a question of how much we could close the gap. we're not as fast in the speed traps but we have more to come.'"
Red Bull ready to go
Red Bull Racing: Thumbs up from Dany. He's good to go for Day Three!
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Lewis Hamilton improves to 1:33.246s before shaving almost three seconds off that time as he continues to rack up the laps early doors.
We're expecting some rain later, so there's a good chance teams will be getting as much running as they can under their belts this morning.
Friday recap
Andrew Benson
Chief F1 writer
"Was Friday the day Formula 1 finally glimpsed the potential of the 2015 Mercedes?
"It had been a low-key pre-season until then, but when Lewis Hamilton unleashed a lap only 0.3secs off the pace on tyres that were at least a second a lap slower than those used by everyone ahead of him, it did not take much imagination to work out what that probably meant. And race simulation runs done simultaneously by Hamilton and Red Bull's Daniel Ricciardo only strengthened that impression. Hamilton's average lap time was a whopping 0.816secs quicker than Ricciardo's.
"They were on different tyre strategies, but that is quite some margin."
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Lewis Hamilton, who recovered from illness to get some track time under his belt on Friday, had snuck his installation lap in before Sebastian Vettel's spin into the gravel, so he is our first driver to pop a time on the board - 1m33.364s.
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Williams: Install lap done, so Felipe Massa returns to the the garage reporting track conditions are 'Okay' #weareracing
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The track is once again green and cars are streaming out. Lewis Hamilton in his Mercedes, as well as Felipe Massa, Pastor Maldonado, Daniil Kvyat and Pacal Wherlein.
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Andrew Benson
Chief F1 writer
"If Sebastian Vettel has indeed lost control of the Ferrari and dropped it on his first lap out of the pits, he can console himself with the thought that he is not the first great champion to suffer such an embarrassment.
"Those with long memories may recall that Alain Prost spun off on the warm-up lap for the 1991 San Marino Grand Prix. Vettel might not want to recall what happened later that season, though. Prost was sacked for making critical comments about the car."
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F1 journalist Dan Knutson in Barcelona: "After two sunny days, a front has moved in on the Circuit De Barcelona-Catalunya and rain is forecast for later in the day.
"The air temperature is 6.8C and the track temperature was 9.4C when the green light at the end of the pit lane signalled the start of the day."
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Sebastian Vettel's stranded Ferrari has been lifted onto the recovery truck and the circuit is clear. Take two...
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Mercedes: Scratch that - red flags out almost instantly. Lewis Hamilton back at base reporting a rather slippery surface.
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Mercedes: "It's green light and away we go! Lewis Hamilton at the wheel today... let's do this!"
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Andrew Benson
Chief F1 writer
"Oops. Not a good start to the day for Sebastian Vettel, who has taken over the Ferrari from Kimi Raikkonen for the final two days of the test. The four-time champion has gone off into the gravel on his out lap. The cause of the incident is unclear for now, but it appears as if the German may have lost the car approaching Turn Five and simply spun."
Red flag
...and is in the gravel at Turn 5. Looks like he spun off. He is out of his car and out comes the red flag.
Go! Go! Go!
The circuit is open and no messing about from Sebastian Vettel, he is straight out for Ferrari...
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F1 journalist Dan Knutson: "After two sunny days, a front has moved in on the Circuit De Barcelona-Catalunya and rain is forecast for later in the day. The air temperature is 6.8C and the track temperature is 9.4C as the green light at the end of the pit lane signals the start of the day."
Drive line-up
Here is the driver line-up for today:
Mercedes: Lewis Hamilton
Red Bull: Daniil Kvyat
Williams: Felipe Massa/Valtteri Bottas
Ferrari: Sebastian Vettel
McLaren: Jenson Button
Force India: Pascal Wehrlein
Toro Rosso: Max Verstappen
Lotus: Pastor Maldonado
Sauber: Marcus Ericsson
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Andrew Benson
Chief F1 writer
"Half-distance in the team's preparations for Formula 1 has passed, and there are only six days left before the cars finish pre-season testing and are packed up and then sent to Australia for the first race of the season.
"So far, testing has been intriguing. Ferrari appear to have made a genuine step forward, Williams and Red Bull will be in the mix, and McLaren-Honda look as if they might just finally be extricating themselves from the mire of unreliability that afflicted their first five days of 2015. But Mercedes, clearly and obviously, remain the team to beat.
"Will those impressions be changed over the forthcoming six days, starting this morning at the demanding Circuit De Barcelona-Catalunya?"
The clock is ticking
Twenty one days and 21 hours; 31,500 minutes; 1,890,000 seconds. Whichever way you look at it, the first race of the 2015 Formula 1 season is fast approaching.
Just over three weeks until lights out at the Australian GP, and we have just passed the halfway mark in pre-season testing.
Is the reigning champion looking in good shape? Who could be his biggest challengers? All that and more could become clearer this weekend...