Can Nico Rosberg convert pole into a much needed victory on Sunday? Or will Lewis Hamilton step it up and storm to another win?
We'll be back on Sunday at 11:30 BST with all the build-up, with the Spanish Grand Prix getting under way at 13:00.
Until then, goodbye.
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OK, it is almost time for us to wrap things up. I'll leave you with Andrew Benson's report from qualifying, and keep an eye online for the video highlights.
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Toro Rosso as a whole were superb. Aside from Carlos Sainz qualifying fifth, his team-mate Max Verstappen will start from sixth on Sunday, ahead of both Red Bulls.
Their performance is all the more impressive when you consider that they are apparently not introducing any major upgrades until the Austrian GP...
Special for Sainz
EPACopyright: EPA
A special mention also for Carlos Sainz, who produced his best ever qualifying performance with fifth and, to top it, off he has done it at his home race.
"It's something special," he said. "Dreaming is free, no? A P5 tomorrow will be very difficult but we'll try our best."
Sainz, of course, is the son of former World Rally champion Carlos Sainz.
APCopyright: AP
Deja vu
Getty ImagesCopyright: Getty Images
Incidentally, the top three from qualifying from that race weekend [see 14:35] was the exact same as today - Nico Rosberg, Lewis Hamilton and Sebastian Vettel.
Stats good to know
The percentages are in Nico Rosberg's favour for Sunday's race. Since the first race at Circuit de Catalunya in 1991, 92% of the races on the circuit have been won from the front row, with 18 of those wins from pole and four from second.
However, there's one bit of bad news from history for Rosberg. Only two of the last 10 races have not been won from pole. One of those two was in 2013, when Fernando Alonso won after Rosberg had started on pole.
Get involved - #bbcf1
Grant Kennett: Interesting to see if Vettel can hound the notoriously wider Merc of Lewis in the same way he has Rosberg's.
Nathan Stewart: Nico needs to save his season and capitalise tomorrow and be in front after the first corner.
Female-F1: Raikkonen was never a strong qualifier. He's a racer. Can't wait to see Lewis playing catch-up tomorrow, that should be entertaining!
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Formula 1Copyright: Formula 1
Ferrari driver Sebastian Vettel, who will start from third: "I think disappointed is the wrong word I think it is great for Ferrari to keep confirming how close we are. This is a great race for us it is very nearly a home race for us.
"You have to say the two guys sat at the side of me (Rosberg and Hamilton) are doing a good job, hopefully tomorrow we can be closer than today but they are doing a good job.
"I didn't do a great job"
Formula 1Copyright: Formula 1
Mercedes driver Lewis Hamilton, who will start from second: "Nico did a great job. I didn't have the balance where I liked. Tomorrow there's still a lot to play for.
"I didn't think I was on the back foot, I just didn't have pace today and didn't do a great job."
"A good day in the office"
A few more words from Nico Rosberg: "Of course I needed it [pole position] sooner rather than later. It is one step in the right direction to winning the race. It was a good day in the office."
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Formula 1Copyright: Formula 1
Mercedes driver Nico Rosberg, who will start on pole on Sunday: "Strategy is important. It's a big advantage to have new set of used tyres for the race. Overtaking is more difficult around here, so starting in front is a big advantage."
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Getty ImagesCopyright: Getty Images
Starting with the 2007 race, the Spanish Grand Prix has seen eight different winners in the last eight years. Those are: Felipe Massa, Kimi Raikkonen, Jenson Button, Mark Webber, Sebastian Vettel, Pastor Maldonado, Fernando Alonso and Lewis Hamilton.
Can Nico Rosberg continue that trend tomorrow and make it nine different drivers in the last nine years?
Get involved - #bbcf1
James Chattaway: Fair play Nico, showing some fight after all.
Max Baggins-Craig: Great effort from Hamilton, but as we know he's been far better of the two, great interesting race tomorrow, beers chilling...
Rachel T: Lewis is going to thoroughly enjoy attacking his teammate into turn one tomorrow.
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F1Copyright: F1
That's Nico Rosberg's first pole position since the final race of last season in Abu Dhabi.
Rosberg will be hoping one aspect of his season continues tomorrow - he has finished every race in the position he has started in this year...
The grid
1) Nico Rosberg 2) Lewis Hamilton 3) Sebastian Vettel 4) Valtteri Bottas 5) Carlos Sainz 6) Max Verstappen 7) Kimi Raikkonen 9) Felipe Massa 10) Daniel Ricciardo
11) Romain Grosjean 12) Pastor Maldonado 13) Fernando Alonso 14) Jenson Button 15) Felipe Nasr 16) Marcus Ericsson 17) Nico Hulkenberg 18) Sergio Perez 19) Will stevens 20) Roberto Merhi
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Superb from Nico Rosberg as he takes the fight to Lewis Hamilton, denying the Briton a fifth successive pole position and giving himself a shot in the arm in the title race.
Hamilton qualifies second with Sebastian Vettel third.
AFP/GETTYCopyright: AFP/GETTY
Pole position
Getty ImagesCopyright: Getty Images
NICO ROSBERG TAKES POLE POSITION FOR THE SPANISH GRAND PRIX.
First qualifying ends
Nico Rosberg is pushing as the chequered flag comes out, but it looks like he has done enough to out qualify his team-mate for the first time this season...
AFP/GETTYCopyright: AFP/GETTY
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Has Lewis Hamilton got anything in his locker? Seconds left of the final part of qualifying...
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Into the final two minutes and all the top 10 will make their final qualifying runs, with four drivers who didn't head out earlier saving their tyres for the race.
Get involved - #bbcf1
Buub Brussee: So good to see that McLaren succeeded their announced updates... #giantsteps ;-((((
Shohidur Rahman: Rosberg has finally turned up. It only took 5 races.
Jason Lewis: So improvement for McLaren but still well off the qualifying pace, hopefully race pace will be better.
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Formula 1Copyright: Formula 1
At the moment it is Nico Rosberg from Lewis Hamilton, Sebastian Vettel, Valtteri Bottas, Kimi Raikkonen and Max Verstappen after the first of the final qualifying runs.
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Lewis Hamilton goes top with 1:24.948 but he is nudged off immediately by Nico Rosberg, who goes almost three tenths quicker. This is going to be close.
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Lee McKenzie has just caught a word with Jenson Button, will start Sunday's race from 14th: "We put new brakes on for qualifying, I don't know what is going on with them but I had really big issues with the car all over the place."
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WilliamsCopyright: Williams
Valtteri Bottas is the first to head out on track, Lewis Hamilton and Kimi Raikkonen follow soon after.
Final qualifying starts
Lewis Hamilton has not been off the front row since Hungary, a run of 12 races and counting. Will he keep that run going?
The fight for pole is under way.
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Superb work from Carlos Sainz and Max Verstappen as they get Toro Rosso into the top 10 shootout at the Circuit de Catalunya for the first time ever.
Who, though, is going to start tomorrow's race on pole? We'll know in just over 10 minutes.
IN
1) Nico Rosberg 2) Lewis Hamilton 3) Kimi Raikkonen 4) Felipe Massa 5) Sebastian Vettel 6) Valtteri Bottas 7) Max Verstappen 8) Carlos Sainz 9) Daniel Ricciardo 10) Daniil Kvyat
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Sadly there will be no Q3 appearance for McLaren as Fernando Alonso and Jenson Button are eliminated. Still, a good step forward.
OUT
11) Romain Grosjean 12) Pastor Maldonado 13) Fernando Alonso 14) Jenson Button 15) Felipe Nasr
Second qualifying ends
Nico Rosberg finishes fastest in the second part of qualifying for the Spanish Grand Prix.
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The top five all decide they have done enough, who will be joining them in Q3?
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Nico Rosberg's time would already have been good enough for pole last year. His time is 0.066s quicker than Lewis Hamilton's pole lap of 1:25.232.
AFPCopyright: AFP
Just over a minute left and everyone from sixth and below on the timesheet are back out.
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All 15 have popped out to stick a time on the board before returning to the pits.
The top 10 order is: Rosberg, Hamilton, Raikkonen Vettel, Bottas, Verstappen, Massa, Sainz, Ricciardo, Kvyat. In danger as things stand are: Alonso, Grosjean, Maldonado, Button, Nasr.
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Lewis Hamilton temporarily goes P1 with 1:25.740 but Nico Rosberg is purple through every sector and posts a mighty fine 1:25.166 straight out of the box. That will make Hamilton sit up and take notice!
Get involved - McLaren through to Q2 #bbcf1
Jason Lewis: Both McLaren's through to Q2 for the first time in 2015, the new lighter paint is paying off!
Kellan Jensel: But the McLaren's used the medium compound tire to desperately get through.
That_guy_moha: McLaren are having a great weekend so far. Maybe it's the change of colour. Good luck to them.
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Felipe Nasr gets things up and running in Q2 with a 1:28.986 before the 14 other cars head out and join him on the circuit. Everyone is out on the medium compound tyre.
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McLarenCopyright: McLaren
McLaren: Minor setup tweaks ahead of Q2 - but the cars are ready to go.
Second qualifying starts
Felipe Nasr is the first man on the circuit for the second part of qualifying.
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Also, some good news for McLaren - Jenson Button and Fernando Alonso have made it through to Q2 for the first time this season.
Getty ImagesCopyright: Getty Images
Can they go even further and get into Q3?
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Mercedes on Twitter: Only Hamilton, Rosberg and Vettel remained on primes in Q1 - all others took a set of options.
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Things are looking good for Carlos Sainz at his home race.
No Toro Rosso has ever started in the top-10 in Catalunya, could the Spaniard be about to change that?
IN
1) Lewis Hamilton 2) Nico Rosberg 3) Kimi Raikkonen 4) Carlos Sainz 5) Felipe Massa 6) Valtteri Bottas 7) Pastor Maldonado 8) Romain Grosjean 9) Max Verstappen 10) Sebastian Vettel
11) Daniel Riccardo 12) Felipe Nasr 13) Jenson Button 14) Daniil Kvyat 15) Fernando Alonso
OUT
16) Marcus Ericsson 17) Nico Hulkenberg 18) Sergio Perez 19) Will Stevens 20) Roberto Merhi
First qualifying ends
Lewis Hamilton is fastest in the first part of qualifying for Spanish Grand Prix.
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While his team-mate Sebastian Vettel is on hard tyres, Kimi Raikkonen has been sent on the medium compound and he goes second with 1:26.490. However, just to highlight the pace Mercedes' possess, Lewis Hamilton goes fastest of all on the slower hard tyre with 1:26.382.
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Daniil Kvyat, Romain Grosjean, Pastor Maldonado, Will Stevens and Roberto Merhi are the five in the drop zone with two minutes left.
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Pirelli on Twitter: Track temperatures in excess of 40 degrees; most teams will try to get through Q1 on the hard tyre, before medium for Q2.
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The McLarens do indeed head out and complete their first timed laps, with Fernando Alonso and Jenson Button, both on medium tyres, going fifth and sixth fastest respectively.
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McLarenCopyright: McLaren
McLaren: The engines are on and the boys are off. Stay tuned for team radio & stats throughout quali.
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Lewis Hamilton is three tenths of a second quicker than Nico Rosberg on the harder compound and he climb into P1, but then complains of poor grip - a common complaint from the drivers so far this week. The top five is currently Hamilton, Rosberg, Sebastian Vettel, Felipe Massa and Carlos Sainz - all setting their best time on the hard tyres.
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Lewis Hamilton warms up with a 1:35.685 before Nico Rosberg goes fastest with 1:27.677. Seventeen drivers have clocked timed laps now with eight minutes left.
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Lewis Hamilton and Nico Rosberg, on the hard tyres, head out as the circuit starts gets busier.
Roberto Merhi kicks things off with a 1:32.038, before Nico Hulkenberg goes fastest with 1:28.677.
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Roberto Merhi is the first out on the circuit, with medium-compound tyres bolted on his Marussia.
First qualifying starts
The clock has started ticking down and 18 minutes of the first part of qualifying is under way.
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LotusCopyright: Lotus
Lotus: Track temp 45 and air temp 24. Not much chance of rain for #Quali.
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Evidently it is baking hot in Barcelona today with plenty of fans at the circuit strolling around with their shirts off. Lewis Hamilton complained of a hot seat in practice yesterday, will it be back to bug him in qualifying too?
If you click the live coverage tab right now you can listen to commentary and team radio from qualifying via BBC Radio 5 live sports extra.
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A trademark smile from Daniel Ricciardo as he greets former Red Bull driver and fellow Australian Mark Webber in the Red Bull garage.
What will he think of his former team's performances so far? Red Bull have not scored a top-five finish in the opening four races of the season, which is their worst-ever start to a season since starting their relationship with Renault in 2007.
A pair of legends
Twenty five years of the Circuit de Catalunya
Getty ImagesCopyright: Getty Images
If you followed Friday's coverage of practice you will have seen we took a step down memory lane to check out some memorable moments from Spanish GPs of the past.
I've been sitting on this one for a while but time to unleash it and showcase Brazil striker Ronaldo's denim shirt and jeans combo in all its glory.
Ronaldo is presenting Michael Schumacher with a shirt before the 1997 Spanish Grand Prix.
The race itself, won by Jacques Villeneuve, was memorable for a Olivier Panis' performance after he climbed from 12th to finish second.
The circuit
BBCCopyright: BBC
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Formula 1Copyright: Formula 1
With 15 minutes to go, here's a reminder of how today will work. There are three stages to qualifying - Q1, Q2 and Q3.
In Q1 drivers have 18 minutes to clock a fast time. The five slowest cars are eliminated once time runs out and will start the race in the final five places on the grid.
In Q2 times are reset and the remaining cars participate in a 15-minute session with the aim of recording a time that will secure their place in the top 10. The five slowest cars are eliminated and fill places 11 to 15 on the grid.
For the final part of qualifying, Q3, times are once again reset and the remaining cars have 12 minutes to clock their fastest possible time as they compete for pole position for the race, as well as the remaining nine places on the grid.
Get involved - can McLaren make the top 10? #bbcf1
Courtland Adams: With a little luck. I see them coming close, around P11/12. Sauber had better watch out!
David Morgan: Possibly not, but getting into Q2 would be a massive step in the right direction.
Ben: With a mighty sector 3 I think there's always a chance. Alonso is renowned for getting everything out of the car, so why not?
Lewis Hamilton spun in final practiceImage caption: Lewis Hamilton spun in final practice
"It's a glorious spring day in Montmelo, and anticipation is mounting at the Circuit De Barcelona Catalunya ahead of what should be a fascinating qualifying session.
"After Mercedes dominated Friday practice, the world champions appeared totally in control of the weekend, but the picture looks somewhat different after final practice this morning. Sebastian Vettel split the Mercedes, less than 0.2secs off pace-setter Nico Rosberg, and Lewis Hamilton had a huge spin at Turn Three, avoiding the wall, but ripping a hole through the tread to the structure of his front left Pirelli underneath, narrowly avoiding tearing the tyre apart. Mercedes suddenly look a lot less serene.
"The Ferrari is good in high-speed corners, and is gentle on its tyres, a great strength at this demanding track. And the red car has tweaks to virtually every aerodynamic surface here. So Vettel and Kimi Raikkonen should be strong in theory. But Mercedes always seem to have that bit extra in qualifying."
More than just a paint job
BBCCopyright: BBC
The McLaren's new livery looks pretty swish but have you had a closer look at the updated car? If not, let Tom Clarkson talk you through it.
While we are it, why not check out our feature on Formula 1's best colour schemes, as voted for by you in our vote during practice on Friday.
A sizeable difference
Getty ImagesCopyright: Getty Images
Pole sitter Nigel Mansell leads from the front at the start of the 1992 Spanish GPImage caption: Pole sitter Nigel Mansell leads from the front at the start of the 1992 Spanish GP
Williams have the largest and smallest pole margins in history at the Circuit de Catalunya.
Nigel Mansell holds the record for the former after securing pole in 1992 by 1.005s, while Pastor Maldonado has the latter, his pole in 2012 beating Ferrari's Fernando Alonso by just 0.017s.
Get involved - qualifying predictions #bbcf1
John Howard: Hamilton... But not fussed if it's Rosberg, Hamilton will school him tomorrow on how to pass a teammate.
Max Baggins-Craig: Hamilton, being best & is more deserved. 1 McLaren in top 10. Verstappen's being suprisingly good, glad to see young'uns have a chance.
Dan Young: It should be Hamilton but going to be close between him Rosberg and Vettel.
Progress for McLaren
Could this prove to be a good day for McLaren?
They've endured their worst start to a Formula 1 season but there's certainly been signs of improvement in Spain so far.
Jenson Button was 10th in third practice earlier today, with Alonso 13th, three tenths of a second behind. Button's fastest time was 1.9s off Nico Rosberg's benchmark, but that is considerable improvement on Australia, when he was almost four seconds off Lewis Hamilton's FP3 time.
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Getty ImagesCopyright: Getty Images
The standings
Formula 1Copyright: Formula 1
Here's a reminder of the standings. The Circuit de Catalunya is one of the hardest on which to overtake, making pole even more important here than at most other circuits.
If Nico Rosberg does fail to out qualify Lewis Hamilton thens save for a retirement for the latter, it is hard not to see Hamilton leaving Spain without his advantage increased.
Get involved #bbcf1
We've got around 45 minutes until qualifying gets under way so let's be having your predictions. Who's taking pole and why? Can McLaren get into to the top 10? Has anyone surprised you so far in Spain and why?
Get involved via the usual methods, on Twitter #bbcf1, text in on 81111 (UK only) or have your say on the BBC Sport Facebook page.
A fillip for Ferrari?
Getty ImagesCopyright: Getty Images
Ferrari have the best record in qualifying for the Spanish Grand Prix, having started from the front on seven occasions.
Williams are next with five, ahead of McLaren on four and Benetton, Red Bull and Mercedes on two.
"Nico Rosberg was 0.156 seconds quicker than Sebastian Vettel in final practice with Lewis Hamilton 0.045secs adrift.
"The times suggest a major step forward for Ferrari after Mercedes dominated throughout Friday practice. The relative pace of Mercedes and Ferrari suggests a close battle for pole position when qualifying starts at 13:00 BST."
Welcome to our coverage of qualifying for the Spanish Grand Prix.
A cursory glance at the results from the three practice sessions would suggest it is as you were in Formula 1 after a three-week break, with Mercedes once again dominating - Nico Rosberg topping FP1 and FP3, and Lewis Hamilton on top in FP2.
However, Ferrari have brought with them significant updates to Barcelona, and certainly looked on the pace earlier today...
Make or break?
Getty ImagesCopyright: Getty Images
We may be just five races in, but time is already against Nico Rosberg.
The German trails Lewis Hamilton by 27 points in the championship, an advantage he won't want to see get much bigger, but he has not beaten his Mercedes team-mate in a race or in qualifying this year.
Could that be about to change?
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Right then, time to grab a quick bite to eat before we return for qualifying build up at 12:00 BST. Join us again then. See you shortly!
How important is pole in Spain?
Getty ImagesCopyright: Getty Images
Lewis Hamilton won last year's Spanish Grand Prix from pole positionImage caption: Lewis Hamilton won last year's Spanish Grand Prix from pole position
Historically, securing pole is vital at the Spanish Grand Prix, with eight of the last 10 pole sitters having gone on to take victory.
The two exceptions were Mark Webber in 2011, when he took pole but Red Bull team-mate Sebastian Vettel won the race, and 2013, when Fernando Alonso won for Ferrari after Mercedes' Nico Rosberg had started at the front of the pack.
Who will take pole today? Not too long until we find out, with qualifying getting under way at 13:00 BST.
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Getty ImagesCopyright: Getty Images
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Fred Owen: Rosberg looks on form for a strong qualifying. Want to see him snatch a pole!
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Nico Rosberg finishes fastest with 1:26.021, with his team-mate Lewis Hamilton third and Sebastian Vettel splitting the Mercedes. There was not much at all between all three, with just two tenths separating them.
Have Ferrari turned up the wick?
Final practice results
1. Rosberg 2. Vettel 3. Hamilton 4. Bottas 5. Raikkonen 6. Ricciardo 7. Massa 8. Verstappen 9. Kvyat 10. Sainz 11. Button 12. Hulkenberg 13. Nasr 14. Alonso 15. Grosjean 16. Maldonado 17. Ericsson 18. Perez 19. Stevens 20. Merhi
Chequered flag
MercedesCopyright: Mercedes
NICO ROSBERG FINISHES FASTEST IN FINAL PRACTICE FOR THE SPANISH GRAND PRIX.
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MercedesCopyright: Mercedes
Mercedes confirm that's it from them as far as timed laps are concerned, so it looks like Nico Rosberg will finish with the fastest time in FP3...
Get involved - drivers as movie characters #bbcf1
In Oxford: Not quite superhero but Will Stevens as Robin Hood... and his Merhi men :-D
Chris Dunn: Surely Maldonado would be Magnito? A clear explanation as to his propensity to crash into everyone/thing; magnetic attraction.
Matt: Mark Webber could be superman. He can fly...
BBCCopyright: BBC
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Tom Clarkson
BBC F1 pit-lane reporter
"We have the longest run to turn one of the season here and everyone is doing practice starts now because there are not many opportunities to nail those start procedures."
Ferrari team radio
Raikkonen's race engineer: "OK, Kimi, we have a wrong setting." Raikkonen sarcastically: "Excellent. Excellent."
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Not a brilliant lap from Kimi Raikkonen as he posts the fifth fastest time, a 1:26.944.
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Nico Rosberg now has the benchmark time with a 1:26.021, just one tenth quicker than Sebastian Vettel. Lewis Hamilton, meanwhile, goes third fastest with his first effort in this run in the closing stages, 0.201s off his team-mate. Not much between all three.
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WilliamsCopyright: Williams
Valtteri Bottas goes quickest on the faster medium tyre with a 1:26.682 but his stay at the top is short as Nico Rosberg and then Sebastian Vettel go a shade faster.
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Into the final 10 minutes of final practice and the circuit is about to get very busy for the closing stages. A reminder of the best time of FP3 last year, a 1:25.887 set by Nico Rosberg.
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With almost everyone off the circuit as they get ready for their qualifying runs, there is just Daniil Kvyat pounding the track as he makes up for lost time. He takes advantage of the clear circuit to go 10th fastest with a 1:28.795.
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Tom Clarkson
BBC F1 pit-lane reporter
"It is pretty quiet down here in the pit lane, except at Ferrari. They have been working on the front brakes on Kimi Raikkonen's car. Only 13% of this lap at this circuit is spent braking, so it is not a heavy braking circuit, but Kimi has not been completely comfortable with his car. It will be interesting to see if he can match the pace of Sebastian Vettel."
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Romain Grosjean, like Pastor Maldonado, has "Mad Max" splashed all over his Lotus. It's just a few stickers, not the below car, although that would be awesome.
Romain GrosjeanCopyright: Romain Grosjean
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"There's something consistently not right," complains Romain Grosjean over team radio. The Lotus man has the 13th fastest time in this session so far.
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PirelliCopyright: Pirelli
Get involved - drivers as movie characters #bbcf1
Just Richard: Max Verstappen as Ferris Bueller, decided to skip school & race in F1.
Scott Leader: Lewis Hamilton as John Mclane, those Germans always trying to win, but him always coming out on top ;)
Steve Barnes: Graham Hill as Bond. James Bond. Suave, classy, and always being chased in Monaco!
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BBCCopyright: BBC
Here is how the top 10 in FP3 looks, with just a handful of cars on the circuit at the moment.
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Tom Clarkson
BBC F1 pit-lane reporter
"Daniil Kvyat is in the car and will be getting out any moment now."
So far so good for McLaren, with Fernando Alonso currently P7 and Jenson Button P11, a reverse of how they finished up in second practice on Friday.
No one has got their qualifying simulation under way, with that happening towards the end of this session. Twenty two minutes left...
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Having managed to avoid the barriers, Lewis Hamilton is able to recover without any drama and get his car back to the pits.
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Tom Clarkson
BBC F1 pit-lane reporter
"One of the reasons Lewis ran wide there is because you need to get back on the power as quickly as possible through Turn 3. You have a crosswind, so the car will be shaking because the air is going across the car."
Spin!
Lewis Hamilton spins at the exit of Turn 3, close to where Fernando Alonso crashed in pre-season testing, and is parked across the circuit, kicking up a huge plume of dust as he hits the brakes.
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Lewis Hamilton is immediately on the pace as a 1:26.965 sees him slot into P2, with his Mercedes team-mate providing a very familiar feel to the order by moving into P1 with a 1:26.777.
Rosberg set the best lap time in P3 last year with a 1:25.887.
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PirelliCopyright: Pirelli
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As Nico Rosberg pops up into P3 with a 1:27.418, Lewis Hamilton has climbed back into his Mercedes and joins his team-mate on the circuit.
Get involved - drivers as movie characters #bbcf1
Lucy Ann: Jenson Button as Jack from Titanic because he doesn't abandon a sinking ship?
Alexander P: Alain Prost as Bruce Banner? The hair... and the nickname. "The Professor"
Jeelan Sumaria: Maldonado as the Joker. He's certainly an agent of chaos.
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FerrariCopyright: Ferrari
Kimi Raikkonen is shaving seconds off his time at the top of the timesheet, with his latest effort a 1:27.330.
Raikkonen was responsible for some team radio gold on Friday as he got increasingly frustrated about going round and round the circuit, remarking: "Do you want to keep going doing laps and laps? Because I get absolutely nothing out of this."
Fifteen drivers have completed timed laps now.
Get involved - drivers as movie characters #bbcf1
Fernando seems to have beaten us to this one, tweeting his alter ego last year...
Fernando AlonsoCopyright: Fernando Alonso
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After popping out for an out lap, Lewis Hamilton is now sat reclining in pretty comfortable looking chair in the Mercedes garage.
Everyone except Daniil Kvyat has been out on the circuit, with the Russian's Red Bull still being worked on. Just under 40 minutes of the session remaining.
"A step in the right direction"
Getty ImagesCopyright: Getty Images
Like pretty much all the teams in Barcelona, Ferrari arrived armed with new updates.
On Friday, Sebastian Vettel fared better than his team-mate Kimi Raikkonen, who struggled all day with the conditions, with the German splitting the Mercedes in FP2 by finishing second. A solid showing, but nothing to get the juices flowing.
So, are the updates working as hoped?
"Well, as usual if you bring new parts you have to confirm them on the track - and to make a verdict after only one day on a rather green track is hard to do," explained Vettel. "I think after qualifying we will have a clearer picture, but my gut feeling is that it is a step in the right direction. If we didn't have that impression there would be no reason to bring them."
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The Ferraris have joined the fray and swiftly move top of the order as Kimi Raikkonen clocks a 1:27.330 to move into P1, with Sebastian Vettel half a second slower in second.
Alonso to miss Spanish GP?
What the papers say
The TimesCopyright: The Times
He is out on the circuit for final practice, but is Fernando Alonso's bad luck at the Circuit de Catalunya set to continue?
The Times reports that he is currently recovering from an inflammation of his eye, which could even rule him out of Sunday's race if he is not deemed fit enough by doctors.
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Tom Clarkson
BBC F1 pit-lane reporter
"Fernando Alonso has just come in for a new front wing, they are playing about with that at the moment. It is interesting with the new livery, it is darker, but it is actually lighter - it weighs less.
"McLaren are really making progress and I am pretty sure one of their cars will get into Q3? Maybe both could get into Q3, it will be interesting to find out."
McLaren making progress?
Getty ImagesCopyright: Getty Images
McLaren are showcasing more than just shiny new livery this weekend. They arrived in Spain this week armed with a whole host of upgrades.
"We have aerodynamic upgrades here this weekend, we have some engine, reliability upgrades," said McLaren managing director Jonathan Neale. "And importantly Exxon Mobil have delivered us a fuel upgrade here as well."
There was certainly reason to be optimistic after Friday's showing in practice as Jenson Button was seventh fastest with Fernando Alonso 11, suggesting they could finally be set to battle for the points on this weekend.
But, as ever, it is in qualifying and the race when it counts.
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There'll be cheers from the early risers in the stands as Fernando Alonso rolls out for the first time today.
"It was another dark day for Red Bull on the reliability front on Friday. Daniel Ricciardo managed only 13 laps all day and got out for only the last five minutes of the second session. The engine fitted to replace the one that had failed was Ricciardo's fourth engine - so he has now used all his allocated units for the season at only the fifth race.
"Grid penalties are inevitable for Ricciardo at some point, and he is desperately hoping he does not lose another engine and have to take a grid drop at Monaco next time around. 'We expected today to be limited with mileage,' said Ricciardo.
"'Obviously we had to put in the fourth engine, which I guess was on the plan. With the laps we did, we have a lot to learn. It would have been nice to get more running. We had quite a few updates today, so trying to get them working in the correct window is something that we have to discover. We all know it's not quite acceptable. It's out of my control. I'm doing what I can with what I've got.'"
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A few more drivers complete their first timed laps. Daniel Ricciardo, who managed just 13 laps on Friday, is making up for lost time and completes an unexceptional lap, some five seconds slower than Felipe Nasr's effort. He soon improves, though, a 1:29.027 putting him top of the early order.
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Lewis Hamilton and Nico Rosberg join the fun on the circuit, both on hard tyres, before Felipe Nasr puts the first time on the board, a 1:31.478.
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Manor on Twitter: Buenos Dias from Catalunya. It's a beautiful sunny day here. Perfect conditions for FP3 & qualifying.
Speaking of sunny, here's Roberto Merhi ready to jump in his car.
Manor F1Copyright: Manor F1
Not so bad news for Red Bull
Panic not, Red Bull fans, Tom has just provided another update swiftly on the back of that one and it is apparently just a water leak they are dealing with. Red Bull hope to get Daniil Kvyat out in the next 30 minutes or so.
Bad news for Red Bull?
Tom Clarkson
BBC F1 pit-lane reporter
"There are no happy faces at Red Bull. Why am I always the bearer of bad news? There is good news, Daniel Ricciardo is in his car, he had a lousy day on Friday, next door however, Daniil Kvyat's car is up on the jacks and surrounded by engineers..."
Get involved #bbcf1
F1 stars as famous film characters
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David Coulthard as Superman?Image caption: David Coulthard as Superman?
Mad Mal as Mad Max? This needs to happen.
With that in mind, if any Formula 1 driver - past or present - could be a film character, who would they be and why? Let us know via #bbcf1, text us on 81111 (UK only) or have your say on the BBC Sport Facebook page.
Mad Mal?
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Speaking of Mad Max, here is a brilliant picture of Pastor Maldonado in a Lotus given a post-apocalyptic makeover.
Given the fact the films feature numerous cars involved in spectacular crashes, the above picture could hardly be more appropriate.
"We think Pastor may just have found his perfect F1 car," tweeted Lotus.
Bad times when even your own team is trolling you...
The back went boom
Formula 1Copyright: Formula 1
One of the more memorable moments from a largely uneventful day of practice on Friday was the engine cover on Romain Grosjean's Lotus spectacularly blowing off.
The team has explained it as a "failure of a bodywork fastening". Yawn. I much prefer Grosjean's explanation.
"It was a convertible car option," he said.
"I think it's just a small part of carbon that probably broke and then air went into the engine cover and it just made a big Mad Max explosion. I saw it in the mirror, for some reason I was looking in the mirror at that time so I saw it live, and I braked early and radioed to say I had lost something."
Go! Go! Go!
Off we go then, one hour of practice is under way. Pastor Maldonado is the first man out on the track.
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A truly beautiful day in Barcelona and it looks like it will be a cracking day out for the fans in attendance. Will Fernando Alonso be able to give the home fans something to cheer about in qualifying later today?
"How bad has it been for Ferrari this weekend, on the evidence of Friday? Well, Sebastian Vettel was 0.8 seconds off the fastest Mercedes - Nico Rosberg's - after the first runs in first practice, and a second behind by the end.
"On the first runs, on the hard tyre, in second practice, Lewis Hamilton was 1.2secs quicker than Vettel, and then half a second clear on the qualifying simulation runs on the mediums.
"The two Mercedes drivers were then neck-and-neck on race pace - a second on average faster than the Ferraris. There's something of a pattern developing there, obviously."
"Ferrari's resurgence this year has re-energised Formula 1, particularly in Germany and Italy, where television audiences that had declined last year have rebounded now Mercedes face some opposition.
"The Italian team have brought significant revisions to their car to this race hoping they would further reduce the gap, on a track where the Ferrari's gentleness on its tyres should in theory pay dividends. But the early signs are not good for them.
"On Friday, Mercedes appeared to have a bigger advantage than at any race since the season-opening Australian Grand Prix - and unusually Ferrari were further behind in race trim than over one lap. Can they do anything about it overnight?"
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Buenos dias! It's qualifying day for the Spanish Grand Prix and boy could it prove to be an intriguing one.
Have McLaren made a big step forward? Are Ferrari closer to Mercedes? Or have their rivals simply stirred a sleeping lion and Mercedes could be set to prove even more dominant?
So many questions to be answered, so settle in and stick with us for the next few hours. We could be in for a belter!
Ferrari - transformers in disguise?
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I don't know about you, but just a little bit of me hoped that Ferrari's new upgrades would transform them into some sort of super rival to Mercedes and really spark up the title race.
That didn't quite transpire on Friday, but could they create a surprise in qualifying?
Live Reporting
Gary Rose
All times stated are UK
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Formula 1Copyright: Formula 1 Lewis Hamilton spun in final practiceImage caption: Lewis Hamilton spun in final practice 
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Latest PostPost update
Can Nico Rosberg convert pole into a much needed victory on Sunday? Or will Lewis Hamilton step it up and storm to another win?
We'll be back on Sunday at 11:30 BST with all the build-up, with the Spanish Grand Prix getting under way at 13:00.
Until then, goodbye.
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OK, it is almost time for us to wrap things up. I'll leave you with Andrew Benson's report from qualifying, and keep an eye online for the video highlights.
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Toro Rosso as a whole were superb. Aside from Carlos Sainz qualifying fifth, his team-mate Max Verstappen will start from sixth on Sunday, ahead of both Red Bulls.
Their performance is all the more impressive when you consider that they are apparently not introducing any major upgrades until the Austrian GP...
Special for Sainz
A special mention also for Carlos Sainz, who produced his best ever qualifying performance with fifth and, to top it, off he has done it at his home race.
"It's something special," he said. "Dreaming is free, no? A P5 tomorrow will be very difficult but we'll try our best."
Sainz, of course, is the son of former World Rally champion Carlos Sainz.
Deja vu
Incidentally, the top three from qualifying from that race weekend [see 14:35] was the exact same as today - Nico Rosberg, Lewis Hamilton and Sebastian Vettel.
Stats good to know
The percentages are in Nico Rosberg's favour for Sunday's race. Since the first race at Circuit de Catalunya in 1991, 92% of the races on the circuit have been won from the front row, with 18 of those wins from pole and four from second.
However, there's one bit of bad news from history for Rosberg. Only two of the last 10 races have not been won from pole. One of those two was in 2013, when Fernando Alonso won after Rosberg had started on pole.
Get involved - #bbcf1
Grant Kennett: Interesting to see if Vettel can hound the notoriously wider Merc of Lewis in the same way he has Rosberg's.
Nathan Stewart: Nico needs to save his season and capitalise tomorrow and be in front after the first corner.
Female-F1: Raikkonen was never a strong qualifier. He's a racer. Can't wait to see Lewis playing catch-up tomorrow, that should be entertaining!
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Ferrari driver Sebastian Vettel, who will start from third: "I think disappointed is the wrong word I think it is great for Ferrari to keep confirming how close we are. This is a great race for us it is very nearly a home race for us.
"You have to say the two guys sat at the side of me (Rosberg and Hamilton) are doing a good job, hopefully tomorrow we can be closer than today but they are doing a good job.
"I didn't do a great job"
Mercedes driver Lewis Hamilton, who will start from second: "Nico did a great job. I didn't have the balance where I liked. Tomorrow there's still a lot to play for.
"I didn't think I was on the back foot, I just didn't have pace today and didn't do a great job."
"A good day in the office"
A few more words from Nico Rosberg: "Of course I needed it [pole position] sooner rather than later. It is one step in the right direction to winning the race. It was a good day in the office."
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Mercedes driver Nico Rosberg, who will start on pole on Sunday: "Strategy is important. It's a big advantage to have new set of used tyres for the race. Overtaking is more difficult around here, so starting in front is a big advantage."
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Starting with the 2007 race, the Spanish Grand Prix has seen eight different winners in the last eight years. Those are: Felipe Massa, Kimi Raikkonen, Jenson Button, Mark Webber, Sebastian Vettel, Pastor Maldonado, Fernando Alonso and Lewis Hamilton.
Can Nico Rosberg continue that trend tomorrow and make it nine different drivers in the last nine years?
Get involved - #bbcf1
James Chattaway: Fair play Nico, showing some fight after all.
Max Baggins-Craig: Great effort from Hamilton, but as we know he's been far better of the two, great interesting race tomorrow, beers chilling...
Rachel T: Lewis is going to thoroughly enjoy attacking his teammate into turn one tomorrow.
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That's Nico Rosberg's first pole position since the final race of last season in Abu Dhabi.
Rosberg will be hoping one aspect of his season continues tomorrow - he has finished every race in the position he has started in this year...
The grid
1) Nico Rosberg 2) Lewis Hamilton 3) Sebastian Vettel 4) Valtteri Bottas 5) Carlos Sainz 6) Max Verstappen 7) Kimi Raikkonen 9) Felipe Massa 10) Daniel Ricciardo
11) Romain Grosjean 12) Pastor Maldonado 13) Fernando Alonso 14) Jenson Button 15) Felipe Nasr 16) Marcus Ericsson 17) Nico Hulkenberg 18) Sergio Perez 19) Will stevens 20) Roberto Merhi
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Superb from Nico Rosberg as he takes the fight to Lewis Hamilton, denying the Briton a fifth successive pole position and giving himself a shot in the arm in the title race.
Hamilton qualifies second with Sebastian Vettel third.
Pole position
NICO ROSBERG TAKES POLE POSITION FOR THE SPANISH GRAND PRIX.
First qualifying ends
Nico Rosberg is pushing as the chequered flag comes out, but it looks like he has done enough to out qualify his team-mate for the first time this season...
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Has Lewis Hamilton got anything in his locker? Seconds left of the final part of qualifying...
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Into the final two minutes and all the top 10 will make their final qualifying runs, with four drivers who didn't head out earlier saving their tyres for the race.
Get involved - #bbcf1
Buub Brussee: So good to see that McLaren succeeded their announced updates... #giantsteps ;-((((
Shohidur Rahman: Rosberg has finally turned up. It only took 5 races.
Jason Lewis: So improvement for McLaren but still well off the qualifying pace, hopefully race pace will be better.
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At the moment it is Nico Rosberg from Lewis Hamilton, Sebastian Vettel, Valtteri Bottas, Kimi Raikkonen and Max Verstappen after the first of the final qualifying runs.
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Lewis Hamilton goes top with 1:24.948 but he is nudged off immediately by Nico Rosberg, who goes almost three tenths quicker. This is going to be close.
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Lee McKenzie has just caught a word with Jenson Button, will start Sunday's race from 14th: "We put new brakes on for qualifying, I don't know what is going on with them but I had really big issues with the car all over the place."
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Valtteri Bottas is the first to head out on track, Lewis Hamilton and Kimi Raikkonen follow soon after.
Final qualifying starts
Lewis Hamilton has not been off the front row since Hungary, a run of 12 races and counting. Will he keep that run going?
The fight for pole is under way.
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Superb work from Carlos Sainz and Max Verstappen as they get Toro Rosso into the top 10 shootout at the Circuit de Catalunya for the first time ever.
Who, though, is going to start tomorrow's race on pole? We'll know in just over 10 minutes.
IN
1) Nico Rosberg 2) Lewis Hamilton 3) Kimi Raikkonen 4) Felipe Massa 5) Sebastian Vettel 6) Valtteri Bottas 7) Max Verstappen 8) Carlos Sainz 9) Daniel Ricciardo 10) Daniil Kvyat
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Sadly there will be no Q3 appearance for McLaren as Fernando Alonso and Jenson Button are eliminated. Still, a good step forward.
OUT
11) Romain Grosjean 12) Pastor Maldonado 13) Fernando Alonso 14) Jenson Button 15) Felipe Nasr
Second qualifying ends
Nico Rosberg finishes fastest in the second part of qualifying for the Spanish Grand Prix.
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The top five all decide they have done enough, who will be joining them in Q3?
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Nico Rosberg's time would already have been good enough for pole last year. His time is 0.066s quicker than Lewis Hamilton's pole lap of 1:25.232.
Just over a minute left and everyone from sixth and below on the timesheet are back out.
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All 15 have popped out to stick a time on the board before returning to the pits.
The top 10 order is: Rosberg, Hamilton, Raikkonen Vettel, Bottas, Verstappen, Massa, Sainz, Ricciardo, Kvyat. In danger as things stand are: Alonso, Grosjean, Maldonado, Button, Nasr.
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Lewis Hamilton temporarily goes P1 with 1:25.740 but Nico Rosberg is purple through every sector and posts a mighty fine 1:25.166 straight out of the box. That will make Hamilton sit up and take notice!
Get involved - McLaren through to Q2 #bbcf1
Jason Lewis: Both McLaren's through to Q2 for the first time in 2015, the new lighter paint is paying off!
Kellan Jensel: But the McLaren's used the medium compound tire to desperately get through.
That_guy_moha: McLaren are having a great weekend so far. Maybe it's the change of colour. Good luck to them.
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Felipe Nasr gets things up and running in Q2 with a 1:28.986 before the 14 other cars head out and join him on the circuit. Everyone is out on the medium compound tyre.
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McLaren: Minor setup tweaks ahead of Q2 - but the cars are ready to go.
Second qualifying starts
Felipe Nasr is the first man on the circuit for the second part of qualifying.
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Also, some good news for McLaren - Jenson Button and Fernando Alonso have made it through to Q2 for the first time this season.
Can they go even further and get into Q3?
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Mercedes on Twitter: Only Hamilton, Rosberg and Vettel remained on primes in Q1 - all others took a set of options.
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Things are looking good for Carlos Sainz at his home race.
No Toro Rosso has ever started in the top-10 in Catalunya, could the Spaniard be about to change that?
IN
1) Lewis Hamilton 2) Nico Rosberg 3) Kimi Raikkonen 4) Carlos Sainz 5) Felipe Massa 6) Valtteri Bottas 7) Pastor Maldonado 8) Romain Grosjean 9) Max Verstappen 10) Sebastian Vettel
11) Daniel Riccardo 12) Felipe Nasr 13) Jenson Button 14) Daniil Kvyat 15) Fernando Alonso
OUT
16) Marcus Ericsson 17) Nico Hulkenberg 18) Sergio Perez 19) Will Stevens 20) Roberto Merhi
First qualifying ends
Lewis Hamilton is fastest in the first part of qualifying for Spanish Grand Prix.
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While his team-mate Sebastian Vettel is on hard tyres, Kimi Raikkonen has been sent on the medium compound and he goes second with 1:26.490. However, just to highlight the pace Mercedes' possess, Lewis Hamilton goes fastest of all on the slower hard tyre with 1:26.382.
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Daniil Kvyat, Romain Grosjean, Pastor Maldonado, Will Stevens and Roberto Merhi are the five in the drop zone with two minutes left.
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Pirelli on Twitter: Track temperatures in excess of 40 degrees; most teams will try to get through Q1 on the hard tyre, before medium for Q2.
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The McLarens do indeed head out and complete their first timed laps, with Fernando Alonso and Jenson Button, both on medium tyres, going fifth and sixth fastest respectively.
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McLaren: The engines are on and the boys are off. Stay tuned for team radio & stats throughout quali.
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Lewis Hamilton is three tenths of a second quicker than Nico Rosberg on the harder compound and he climb into P1, but then complains of poor grip - a common complaint from the drivers so far this week. The top five is currently Hamilton, Rosberg, Sebastian Vettel, Felipe Massa and Carlos Sainz - all setting their best time on the hard tyres.
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Lewis Hamilton warms up with a 1:35.685 before Nico Rosberg goes fastest with 1:27.677. Seventeen drivers have clocked timed laps now with eight minutes left.
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Lewis Hamilton and Nico Rosberg, on the hard tyres, head out as the circuit starts gets busier.
Roberto Merhi kicks things off with a 1:32.038, before Nico Hulkenberg goes fastest with 1:28.677.
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Roberto Merhi is the first out on the circuit, with medium-compound tyres bolted on his Marussia.
First qualifying starts
The clock has started ticking down and 18 minutes of the first part of qualifying is under way.
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Lotus: Track temp 45 and air temp 24. Not much chance of rain for #Quali.
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Evidently it is baking hot in Barcelona today with plenty of fans at the circuit strolling around with their shirts off. Lewis Hamilton complained of a hot seat in practice yesterday, will it be back to bug him in qualifying too?
Just two minutes until qualifying gets under way.
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BBC Radio 5 live sports extra
If you click the live coverage tab right now you can listen to commentary and team radio from qualifying via BBC Radio 5 live sports extra.
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A trademark smile from Daniel Ricciardo as he greets former Red Bull driver and fellow Australian Mark Webber in the Red Bull garage.
What will he think of his former team's performances so far? Red Bull have not scored a top-five finish in the opening four races of the season, which is their worst-ever start to a season since starting their relationship with Renault in 2007.
A pair of legends
Twenty five years of the Circuit de Catalunya
If you followed Friday's coverage of practice you will have seen we took a step down memory lane to check out some memorable moments from Spanish GPs of the past.
I've been sitting on this one for a while but time to unleash it and showcase Brazil striker Ronaldo's denim shirt and jeans combo in all its glory.
Ronaldo is presenting Michael Schumacher with a shirt before the 1997 Spanish Grand Prix.
The race itself, won by Jacques Villeneuve, was memorable for a Olivier Panis' performance after he climbed from 12th to finish second.
The circuit
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With 15 minutes to go, here's a reminder of how today will work. There are three stages to qualifying - Q1, Q2 and Q3.
In Q1 drivers have 18 minutes to clock a fast time. The five slowest cars are eliminated once time runs out and will start the race in the final five places on the grid.
In Q2 times are reset and the remaining cars participate in a 15-minute session with the aim of recording a time that will secure their place in the top 10. The five slowest cars are eliminated and fill places 11 to 15 on the grid.
For the final part of qualifying, Q3, times are once again reset and the remaining cars have 12 minutes to clock their fastest possible time as they compete for pole position for the race, as well as the remaining nine places on the grid.
Get involved - can McLaren make the top 10? #bbcf1
Courtland Adams: With a little luck. I see them coming close, around P11/12. Sauber had better watch out!
David Morgan: Possibly not, but getting into Q2 would be a massive step in the right direction.
Ben: With a mighty sector 3 I think there's always a chance. Alonso is renowned for getting everything out of the car, so why not?
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Andrew Benson
Chief F1 writer
"It's a glorious spring day in Montmelo, and anticipation is mounting at the Circuit De Barcelona Catalunya ahead of what should be a fascinating qualifying session.
"After Mercedes dominated Friday practice, the world champions appeared totally in control of the weekend, but the picture looks somewhat different after final practice this morning. Sebastian Vettel split the Mercedes, less than 0.2secs off pace-setter Nico Rosberg, and Lewis Hamilton had a huge spin at Turn Three, avoiding the wall, but ripping a hole through the tread to the structure of his front left Pirelli underneath, narrowly avoiding tearing the tyre apart. Mercedes suddenly look a lot less serene.
"The Ferrari is good in high-speed corners, and is gentle on its tyres, a great strength at this demanding track. And the red car has tweaks to virtually every aerodynamic surface here. So Vettel and Kimi Raikkonen should be strong in theory. But Mercedes always seem to have that bit extra in qualifying."
More than just a paint job
The McLaren's new livery looks pretty swish but have you had a closer look at the updated car? If not, let Tom Clarkson talk you through it.
While we are it, why not check out our feature on Formula 1's best colour schemes, as voted for by you in our vote during practice on Friday.
A sizeable difference
Williams have the largest and smallest pole margins in history at the Circuit de Catalunya.
Nigel Mansell holds the record for the former after securing pole in 1992 by 1.005s, while Pastor Maldonado has the latter, his pole in 2012 beating Ferrari's Fernando Alonso by just 0.017s.
Get involved - qualifying predictions #bbcf1
John Howard: Hamilton... But not fussed if it's Rosberg, Hamilton will school him tomorrow on how to pass a teammate.
Max Baggins-Craig: Hamilton, being best & is more deserved. 1 McLaren in top 10. Verstappen's being suprisingly good, glad to see young'uns have a chance.
Dan Young: It should be Hamilton but going to be close between him Rosberg and Vettel.
Progress for McLaren
Could this prove to be a good day for McLaren?
They've endured their worst start to a Formula 1 season but there's certainly been signs of improvement in Spain so far.
Jenson Button was 10th in third practice earlier today, with Alonso 13th, three tenths of a second behind. Button's fastest time was 1.9s off Nico Rosberg's benchmark, but that is considerable improvement on Australia, when he was almost four seconds off Lewis Hamilton's FP3 time.
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The standings
Here's a reminder of the standings. The Circuit de Catalunya is one of the hardest on which to overtake, making pole even more important here than at most other circuits.
If Nico Rosberg does fail to out qualify Lewis Hamilton thens save for a retirement for the latter, it is hard not to see Hamilton leaving Spain without his advantage increased.
Get involved #bbcf1
We've got around 45 minutes until qualifying gets under way so let's be having your predictions. Who's taking pole and why? Can McLaren get into to the top 10? Has anyone surprised you so far in Spain and why?
Get involved via the usual methods, on Twitter #bbcf1, text in on 81111 (UK only) or have your say on the BBC Sport Facebook page.
A fillip for Ferrari?
Ferrari have the best record in qualifying for the Spanish Grand Prix, having started from the front on seven occasions.
Williams are next with five, ahead of McLaren on four and Benetton, Red Bull and Mercedes on two.
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Andrew Benson
Chief F1 writer
"Nico Rosberg was 0.156 seconds quicker than Sebastian Vettel in final practice with Lewis Hamilton 0.045secs adrift.
"The times suggest a major step forward for Ferrari after Mercedes dominated throughout Friday practice. The relative pace of Mercedes and Ferrari suggests a close battle for pole position when qualifying starts at 13:00 BST."
Read more from Andrew Benson in his report from final practice.
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Welcome to our coverage of qualifying for the Spanish Grand Prix.
A cursory glance at the results from the three practice sessions would suggest it is as you were in Formula 1 after a three-week break, with Mercedes once again dominating - Nico Rosberg topping FP1 and FP3, and Lewis Hamilton on top in FP2.
However, Ferrari have brought with them significant updates to Barcelona, and certainly looked on the pace earlier today...
Make or break?
We may be just five races in, but time is already against Nico Rosberg.
The German trails Lewis Hamilton by 27 points in the championship, an advantage he won't want to see get much bigger, but he has not beaten his Mercedes team-mate in a race or in qualifying this year.
Could that be about to change?
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Right then, time to grab a quick bite to eat before we return for qualifying build up at 12:00 BST. Join us again then. See you shortly!
How important is pole in Spain?
Historically, securing pole is vital at the Spanish Grand Prix, with eight of the last 10 pole sitters having gone on to take victory.
The two exceptions were Mark Webber in 2011, when he took pole but Red Bull team-mate Sebastian Vettel won the race, and 2013, when Fernando Alonso won for Ferrari after Mercedes' Nico Rosberg had started at the front of the pack.
Who will take pole today? Not too long until we find out, with qualifying getting under way at 13:00 BST.
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Fred Owen: Rosberg looks on form for a strong qualifying. Want to see him snatch a pole!
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Nico Rosberg finishes fastest with 1:26.021, with his team-mate Lewis Hamilton third and Sebastian Vettel splitting the Mercedes. There was not much at all between all three, with just two tenths separating them.
Have Ferrari turned up the wick?
Final practice results
1. Rosberg 2. Vettel 3. Hamilton 4. Bottas 5. Raikkonen 6. Ricciardo 7. Massa 8. Verstappen 9. Kvyat 10. Sainz 11. Button 12. Hulkenberg 13. Nasr 14. Alonso 15. Grosjean 16. Maldonado 17. Ericsson 18. Perez 19. Stevens 20. Merhi
Chequered flag
NICO ROSBERG FINISHES FASTEST IN FINAL PRACTICE FOR THE SPANISH GRAND PRIX.
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Mercedes confirm that's it from them as far as timed laps are concerned, so it looks like Nico Rosberg will finish with the fastest time in FP3...
Get involved - drivers as movie characters #bbcf1
In Oxford: Not quite superhero but Will Stevens as Robin Hood... and his Merhi men :-D
Chris Dunn: Surely Maldonado would be Magnito? A clear explanation as to his propensity to crash into everyone/thing; magnetic attraction.
Matt: Mark Webber could be superman. He can fly...
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Tom Clarkson
BBC F1 pit-lane reporter
"We have the longest run to turn one of the season here and everyone is doing practice starts now because there are not many opportunities to nail those start procedures."
Ferrari team radio
Raikkonen's race engineer: "OK, Kimi, we have a wrong setting." Raikkonen sarcastically: "Excellent. Excellent."
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Not a brilliant lap from Kimi Raikkonen as he posts the fifth fastest time, a 1:26.944.
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Nico Rosberg now has the benchmark time with a 1:26.021, just one tenth quicker than Sebastian Vettel. Lewis Hamilton, meanwhile, goes third fastest with his first effort in this run in the closing stages, 0.201s off his team-mate. Not much between all three.
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Valtteri Bottas goes quickest on the faster medium tyre with a 1:26.682 but his stay at the top is short as Nico Rosberg and then Sebastian Vettel go a shade faster.
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Into the final 10 minutes of final practice and the circuit is about to get very busy for the closing stages. A reminder of the best time of FP3 last year, a 1:25.887 set by Nico Rosberg.
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With almost everyone off the circuit as they get ready for their qualifying runs, there is just Daniil Kvyat pounding the track as he makes up for lost time. He takes advantage of the clear circuit to go 10th fastest with a 1:28.795.
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Tom Clarkson
BBC F1 pit-lane reporter
"It is pretty quiet down here in the pit lane, except at Ferrari. They have been working on the front brakes on Kimi Raikkonen's car. Only 13% of this lap at this circuit is spent braking, so it is not a heavy braking circuit, but Kimi has not been completely comfortable with his car. It will be interesting to see if he can match the pace of Sebastian Vettel."
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Romain Grosjean, like Pastor Maldonado, has "Mad Max" splashed all over his Lotus. It's just a few stickers, not the below car, although that would be awesome.
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"There's something consistently not right," complains Romain Grosjean over team radio. The Lotus man has the 13th fastest time in this session so far.
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Get involved - drivers as movie characters #bbcf1
Just Richard: Max Verstappen as Ferris Bueller, decided to skip school & race in F1.
Scott Leader: Lewis Hamilton as John Mclane, those Germans always trying to win, but him always coming out on top ;)
Steve Barnes: Graham Hill as Bond. James Bond. Suave, classy, and always being chased in Monaco!
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Here is how the top 10 in FP3 looks, with just a handful of cars on the circuit at the moment.
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Tom Clarkson
BBC F1 pit-lane reporter
"Daniil Kvyat is in the car and will be getting out any moment now."
Video
Talking of Turn Three, here's Mad Mal losing it there during qualifying last year. A lot like Hamilton's spin. except Maldonado hit the wall. Quite hard.
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So far so good for McLaren, with Fernando Alonso currently P7 and Jenson Button P11, a reverse of how they finished up in second practice on Friday.
No one has got their qualifying simulation under way, with that happening towards the end of this session. Twenty two minutes left...
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Having managed to avoid the barriers, Lewis Hamilton is able to recover without any drama and get his car back to the pits.
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Tom Clarkson
BBC F1 pit-lane reporter
"One of the reasons Lewis ran wide there is because you need to get back on the power as quickly as possible through Turn 3. You have a crosswind, so the car will be shaking because the air is going across the car."
Spin!
Lewis Hamilton spins at the exit of Turn 3, close to where Fernando Alonso crashed in pre-season testing, and is parked across the circuit, kicking up a huge plume of dust as he hits the brakes.
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Lewis Hamilton is immediately on the pace as a 1:26.965 sees him slot into P2, with his Mercedes team-mate providing a very familiar feel to the order by moving into P1 with a 1:26.777.
Rosberg set the best lap time in P3 last year with a 1:25.887.
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As Nico Rosberg pops up into P3 with a 1:27.418, Lewis Hamilton has climbed back into his Mercedes and joins his team-mate on the circuit.
Get involved - drivers as movie characters #bbcf1
Lucy Ann: Jenson Button as Jack from Titanic because he doesn't abandon a sinking ship?
Alexander P: Alain Prost as Bruce Banner? The hair... and the nickname. "The Professor"
Jeelan Sumaria: Maldonado as the Joker. He's certainly an agent of chaos.
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Kimi Raikkonen is shaving seconds off his time at the top of the timesheet, with his latest effort a 1:27.330.
Raikkonen was responsible for some team radio gold on Friday as he got increasingly frustrated about going round and round the circuit, remarking: "Do you want to keep going doing laps and laps? Because I get absolutely nothing out of this."
Fifteen drivers have completed timed laps now.
Get involved - drivers as movie characters #bbcf1
Fernando seems to have beaten us to this one, tweeting his alter ego last year...
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After popping out for an out lap, Lewis Hamilton is now sat reclining in pretty comfortable looking chair in the Mercedes garage.
Everyone except Daniil Kvyat has been out on the circuit, with the Russian's Red Bull still being worked on. Just under 40 minutes of the session remaining.
"A step in the right direction"
Like pretty much all the teams in Barcelona, Ferrari arrived armed with new updates.
On Friday, Sebastian Vettel fared better than his team-mate Kimi Raikkonen, who struggled all day with the conditions, with the German splitting the Mercedes in FP2 by finishing second. A solid showing, but nothing to get the juices flowing.
So, are the updates working as hoped?
"Well, as usual if you bring new parts you have to confirm them on the track - and to make a verdict after only one day on a rather green track is hard to do," explained Vettel. "I think after qualifying we will have a clearer picture, but my gut feeling is that it is a step in the right direction. If we didn't have that impression there would be no reason to bring them."
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The Ferraris have joined the fray and swiftly move top of the order as Kimi Raikkonen clocks a 1:27.330 to move into P1, with Sebastian Vettel half a second slower in second.
Alonso to miss Spanish GP?
What the papers say
He is out on the circuit for final practice, but is Fernando Alonso's bad luck at the Circuit de Catalunya set to continue?
The Times reports that he is currently recovering from an inflammation of his eye, which could even rule him out of Sunday's race if he is not deemed fit enough by doctors.
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Tom Clarkson
BBC F1 pit-lane reporter
"Fernando Alonso has just come in for a new front wing, they are playing about with that at the moment. It is interesting with the new livery, it is darker, but it is actually lighter - it weighs less.
"McLaren are really making progress and I am pretty sure one of their cars will get into Q3? Maybe both could get into Q3, it will be interesting to find out."
McLaren making progress?
McLaren are showcasing more than just shiny new livery this weekend. They arrived in Spain this week armed with a whole host of upgrades.
"We have aerodynamic upgrades here this weekend, we have some engine, reliability upgrades," said McLaren managing director Jonathan Neale. "And importantly Exxon Mobil have delivered us a fuel upgrade here as well."
There was certainly reason to be optimistic after Friday's showing in practice as Jenson Button was seventh fastest with Fernando Alonso 11, suggesting they could finally be set to battle for the points on this weekend.
But, as ever, it is in qualifying and the race when it counts.
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There'll be cheers from the early risers in the stands as Fernando Alonso rolls out for the first time today.
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Andrew Benson
Chief F1 writer in Barcelona
"It was another dark day for Red Bull on the reliability front on Friday. Daniel Ricciardo managed only 13 laps all day and got out for only the last five minutes of the second session. The engine fitted to replace the one that had failed was Ricciardo's fourth engine - so he has now used all his allocated units for the season at only the fifth race.
"Grid penalties are inevitable for Ricciardo at some point, and he is desperately hoping he does not lose another engine and have to take a grid drop at Monaco next time around. 'We expected today to be limited with mileage,' said Ricciardo.
"'Obviously we had to put in the fourth engine, which I guess was on the plan. With the laps we did, we have a lot to learn. It would have been nice to get more running. We had quite a few updates today, so trying to get them working in the correct window is something that we have to discover. We all know it's not quite acceptable. It's out of my control. I'm doing what I can with what I've got.'"
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A few more drivers complete their first timed laps. Daniel Ricciardo, who managed just 13 laps on Friday, is making up for lost time and completes an unexceptional lap, some five seconds slower than Felipe Nasr's effort. He soon improves, though, a 1:29.027 putting him top of the early order.
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Lewis Hamilton and Nico Rosberg join the fun on the circuit, both on hard tyres, before Felipe Nasr puts the first time on the board, a 1:31.478.
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Manor on Twitter: Buenos Dias from Catalunya. It's a beautiful sunny day here. Perfect conditions for FP3 & qualifying.
Speaking of sunny, here's Roberto Merhi ready to jump in his car.
Not so bad news for Red Bull
Panic not, Red Bull fans, Tom has just provided another update swiftly on the back of that one and it is apparently just a water leak they are dealing with. Red Bull hope to get Daniil Kvyat out in the next 30 minutes or so.
Bad news for Red Bull?
Tom Clarkson
BBC F1 pit-lane reporter
"There are no happy faces at Red Bull. Why am I always the bearer of bad news? There is good news, Daniel Ricciardo is in his car, he had a lousy day on Friday, next door however, Daniil Kvyat's car is up on the jacks and surrounded by engineers..."
Get involved #bbcf1
F1 stars as famous film characters
Mad Mal as Mad Max? This needs to happen.
With that in mind, if any Formula 1 driver - past or present - could be a film character, who would they be and why? Let us know via #bbcf1, text us on 81111 (UK only) or have your say on the BBC Sport Facebook page.
Mad Mal?
Speaking of Mad Max, here is a brilliant picture of Pastor Maldonado in a Lotus given a post-apocalyptic makeover.
Given the fact the films feature numerous cars involved in spectacular crashes, the above picture could hardly be more appropriate.
"We think Pastor may just have found his perfect F1 car," tweeted Lotus.
Bad times when even your own team is trolling you...
The back went boom
One of the more memorable moments from a largely uneventful day of practice on Friday was the engine cover on Romain Grosjean's Lotus spectacularly blowing off.
The team has explained it as a "failure of a bodywork fastening". Yawn. I much prefer Grosjean's explanation.
"It was a convertible car option," he said.
"I think it's just a small part of carbon that probably broke and then air went into the engine cover and it just made a big Mad Max explosion. I saw it in the mirror, for some reason I was looking in the mirror at that time so I saw it live, and I braked early and radioed to say I had lost something."
Go! Go! Go!
Off we go then, one hour of practice is under way. Pastor Maldonado is the first man out on the track.
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A truly beautiful day in Barcelona and it looks like it will be a cracking day out for the fans in attendance. Will Fernando Alonso be able to give the home fans something to cheer about in qualifying later today?
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Andrew Benson
Chief F1 writer in Barcelona
"How bad has it been for Ferrari this weekend, on the evidence of Friday? Well, Sebastian Vettel was 0.8 seconds off the fastest Mercedes - Nico Rosberg's - after the first runs in first practice, and a second behind by the end.
"On the first runs, on the hard tyre, in second practice, Lewis Hamilton was 1.2secs quicker than Vettel, and then half a second clear on the qualifying simulation runs on the mediums.
"The two Mercedes drivers were then neck-and-neck on race pace - a second on average faster than the Ferraris. There's something of a pattern developing there, obviously."
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Hamilton in a league of his own
OK, just a few minutes until one hour of final practice gets under way. The last bit of fine tuning for teams to get their cars ready for qualifying.
A quick reminder of how Friday panned out - Lewis Hamilton was in a league of his own as the Mercedes driver set the fastest time in second practice.
The world champion was 0.408 seconds up on Ferrari's Sebastian Vettel, with Mercedes team-mate Nico Rosberg third.
How's the weather?
It is another beautiful day in Barcelona and it looks set to stay that way, too. With a whopping 1% chance of rain.
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Andrew Benson
Chief F1 writer in Barcelona
"Ferrari's resurgence this year has re-energised Formula 1, particularly in Germany and Italy, where television audiences that had declined last year have rebounded now Mercedes face some opposition.
"The Italian team have brought significant revisions to their car to this race hoping they would further reduce the gap, on a track where the Ferrari's gentleness on its tyres should in theory pay dividends. But the early signs are not good for them.
"On Friday, Mercedes appeared to have a bigger advantage than at any race since the season-opening Australian Grand Prix - and unusually Ferrari were further behind in race trim than over one lap. Can they do anything about it overnight?"
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Buenos dias! It's qualifying day for the Spanish Grand Prix and boy could it prove to be an intriguing one.
Have McLaren made a big step forward? Are Ferrari closer to Mercedes? Or have their rivals simply stirred a sleeping lion and Mercedes could be set to prove even more dominant?
So many questions to be answered, so settle in and stick with us for the next few hours. We could be in for a belter!
Ferrari - transformers in disguise?
I don't know about you, but just a little bit of me hoped that Ferrari's new upgrades would transform them into some sort of super rival to Mercedes and really spark up the title race.
That didn't quite transpire on Friday, but could they create a surprise in qualifying?