07:55 Good morning and welcome to the first AUTOSPORT Live commentary of the 2012 season, as Formula 1 testing kicks off at Jerez.

07:56 Engines are being warmed up in the garages ready for the action to get underway. Conditions are good, with a dry track and just some mist over the back of the circuit.

07:57 Here's today's full forecast from our weather genius @radarguruf1: Tuesday: Weather will be fine with strong sunshine quickly coming through after a misty start. No hint of any cloud all day, but there will be a light northerly breeze. Temp climbing from an overnight low of +3 Celsius. Max air temp 18c, maybe touching 19c mid-afternoon. With continuous sunshine that could pitch track temp up around the 25-30c range in the hour or two after lunch.

07:59 All the teams bar Marussia are present today, and of those in action, Sauber, Ferrari, Force India, Caterham, McLaren, Red Bull, Lotus, Toro Rosso and Williams will have their 2012 cars on track.

08:00 Mercedes and HRT are sticking with their 2011 machines for now, with their 2012 designs expected to appear for the next test in a fortnight.

08:00 We're off: Heikki Kovalainen takes the Caterham out of the pitlane and F1 2012 is underway.

08:01 Next out are Kimi Raikkonen's Lotus and Daniel Ricciardo's Toro Rosso.

08:01 Kamui Kobayashi's Sauber, Nico Rosberg's Mercedes and Paul di Resta's Force India follow on.

08:02 These will just be quick installation runs, with the cars returning to the pits for checks before going for times.

08:02 The air temperature right now is a chilly 3.7 degrees, with a track temperature of 8.9.

08:03 Kobayashi has already brought the Sauber in then rejoined the track.

08:04 Rosberg has stayed out for a second lap, everyone else has returned to the pits.

08:04 Felipe Massa sets off in the new Ferrari for the first time this morning.

08:06 Massa is now the only man on the circuit.

08:07 We've seen seven cars out so far, but nothing from McLaren, Red Bull, HRT or Williams.

08:08 Williams only took the wraps off its new car this morning, launching the Renault-powered FW34 in the pitlane half an hour ago.

08:11 Pastor Maldonado will give the car its first run today, with Bruno Senna making his first appearance in a Williams on Thursday.

08:12 It's all quiet at Jerez at the moment, with the majority of teams having completed installation laps and all returned to the pits. The air temperature has nudged up to 4.1 degrees, track temperature to 12.1.

08:13 Wise observation from AUTOSPORT news editor @glenn_autosport: "Rare that we can read much into F1 testing times, but on the first day last year the Red Bull was the fastest 2011 car by 0.7s from Ferrari"

08:14 Sometimes these tests can be very popular with spectators, but today the stands are empty - it's a working day and local favourite Fernando Alonso is not in action.

08:15 AUTOSPORT's F1 editor @eddstrawF1 explains what to expect from this morning: "The early running today, particularly for those who haven't taken advantage of the opportunity to run the car on a promotional day already, will be to check the basics.

"New cars means new packaging, different cooling systems, modified electronic systems and for teams like Williams, a switch of engine supplier, so early doors the teams will want to check the fundamentals.

"If the car doesn't fall apart or catch fire (very much the worst case scenario) they will continue to gather this kind of data and also try and get a feel for if the car is behaving on track in the same way that the windtunnel and CFD simulation data suggests. The happiest teams will be the ones who discover that the correlation is good as the test goes on."

08:16 Maldonado brings the new Williams out for its first run.

08:16 His out-lap is particularly slow and cautious.

08:17 Williams's chief operation engineer Mark Gillan explained to AUTOSPORT's @eddstrawF1 what the team would be doing on the FW34's first outing: "We have a long checklist of systems checks and operational running of which understanding the cooling, to make sure that we are in the right region of the cooling as expected to make sure that the correlation with the tunnel is good. And understanding the subtle changes of mapping and the way Renault operates compared to our previous supplier."

08:17 Maldonado is trickling back towards the pits now.

08:18 As ever, you can check out all the pics from the Jerez test as they roll in via our constantly updated testing gallery, already packed with images from Monday's set-up day and the Lotus promotional run.

08:19 News from @ToroRossoSpy: "Installation lap completed successfully, now it's time to give the car a thorough check over."

08:20 With Raikkonen in the Lotus cockpit today, Romain Grosjean is standing on the pit wall watching proceedings.

08:20 Jenson Button emerges to give the new McLaren its track debut.

08:20 Raikkonen's Lotus fires up and he sets off for his second run of the morning.

08:22 Button pressing on with an installation lap much faster than the one just seen from Maldonado's Williams.

08:23 Raikkonen heads onto what could be our first flying lap of the day.

08:23 Contrails from the rear wing as he goes through Turn 4. The air is still very moist and there's a hint of mist.

08:23 The Lotus heads through the Dry Sack corner.

08:24 Raikkonen sets a 1m20.992s, our first flying lap of the year.

08:24 Kobayashi brings the Sauber back out.

08:25 Raikkonen improves to 1m20.802s.

08:25 The ex-champion is the only man to set a time so far, and continues onto a third flying lap.

08:26 Di Resta and Rosberg have headed out as well.

08:26 Raikkonen's third lap is slightly slower than the second, a 1m20.839s.

08:28 Kobayashi goes second fastest to Raikkonen with a 1m22.198s.

08:28 Raikkonen laps in 1m21.065s as he goes onto lap five of his run.

08:29 Kobayashi's second lap is slower than his first, he does a 1m22.259s.

08:29 Rosberg is also on the circuit, but is coming through the pits at the end of every lap.

08:30 Raikkonen improves to 1m20.514s, a new best of the morning.

08:31 Raikkonen returns to the pits at the end of his first run. All calm and relaxed at Lotus.

08:32 Kobayashi has pitted too, so just Rosberg on track.

08:34 Rosberg is still out but is doing some form of slow-running tests at the back of the circuit, so his times are only 1m40s.

08:36 AUTOSPORT F1 editor @eddstrawF1 says: "It's no coincidence that the two teams who completed promotional running yesterday - Lotus and Sauber - have completed the most laps of teams with new cars so far.

"As Kamui Kobayashi said yesterday 'we had no problems and went through the programme, so I am happy. It was a good start for us. We can start tomorrow with more detailed testing and are not worried about trouble from the first moment."

08:36 Another 1m40s lap from Rosberg's Mercedes.

08:36 Rosberg comes into the pits.

08:39 Track temperature is up to 16.7 degrees as Maldonado brings the Williams back out. Air temperature still only 4.5.

08:40 This is another very tentative run from Maldonado in the brand new Williams FW34.

08:40 If you have any questions you want to put to AUTOSPORT's team on the ground at Jerez about testing so far, the 2012 cars or any other burning issue, you can email live@autosport.com.

08:40 We'll try to get through as many of your questions as we can, and will also have a few special guests for you to quiz later in the week.

08:42 Massa heads out with a long aero tube on top of the Ferrari's rollhoop.

08:42 The Brazilian took it very easy through Turn 3 before accelerating up to speed.

08:42 Maldonado has brought the Williams back into the pits.

08:44 Massa stays out for a second lap, and is more aggressive this time.

08:44 Massa's first flying lap is a 1m24.423s and he stays out and keeps pushing on.

08:46 Di Resta brings the Force India back out. He's done quite a few laps without setting a time so far.

08:46 Massa comes past the pits in a lower gear this time, perhaps doing a calibration check.

08:46 Ricciardo leaves the pits in the Toro Rosso.

08:48 Massa continues to slow on straights, this is definitely an evaluation run rather than an attempt at performance testing. The Ferrari's last lap was in the 1m41s.

08:50 Ricciardo puts in a 1m31.537s for his first flying lap of the winter.

08:52 Ricciardo improves to 1m25.807s.

08:54 Several of you have asked how the times set so far compare to last year. Very well, is the answer. Raikkonen's 1m20.514s is quicker than the 1m20.709s that Massa set when topping the first day of Jerez testing in February 2011.

08:54 Last year Jerez was the second venue on the testing schedule after a week at Valencia.

08:54 The top time at the end of the 2011 Jerez week was a 1m19.832s from Rubens Barrichello's Williams.

08:55 Given how Williams's season subsequently unfolded, that seems a good time to mention that testing can sometimes be misleading...

08:55 Button has done an out/in run on soft tyres.

08:57 We've had quite a few questions about the tyre allocation for testing. Teams have 25 sets of Pirellis, covering the soft, medium and hard compounds, and are free to run them as they please. We will do our best to identify which compound drivers are using on their runs.

08:57 Raikkonen is back out and pressing on, his slower laps still faster than anyone else is managing so far.

08:57 Rosberg brings the Mercedes out on the medium Pirelli.

08:59 Smiles down at @Lotus_F1Team: "A good start, as Kimi quickly settles into the rhythm in the E20"

09:00 There were reports of a part flying off the new Sauber during Kobayashi's earlier run. @eddstrawF1 has discovered that it was a small part of the rear brake duct and is now being repaired.

09:01 From trackside we can see that Raikkonen is starting to wind it up, and beginning to lean on the car a little more.

09:01 The Finn is the only man on track at the moment.

09:01 And is frankly probably happier than he would've been if he had been preparing for Rally Sweden this weekend...

09:03 Raikkonen comes back in. That run was on the medium tyres. And now the circuit is empty.

09:04 So an hour into 2012 F1 winter testing, and Raikkonen is fastest on a 1m20.514s, 1.5s ahead of Kobayashi, 3.9s ahead of Massa and 4.1s ahead of Ricciardo. Di Resta and Rosberg have only done slower evaluation runs, and no one else has set a time so far.

09:06 A Lotus spokesman tells @StrangAutosport that all is looking good so far, with no dramas and Raikkonen happy in the car.

09:06 Lotus's programme for this morning is mainly focused on giving Raikkonen and the new E20 some mileage.

09:07 @MikeGascoyne provides a Caterham update: "Short break after installation lap while we fit some parts that only turned up this morning. Back out soon."

09:09 Raikkonen took a bite of grass as he entered the pitlane. Not hanging about even on his in-lap. There is purpose in his body and car language.

09:10 News from the pitlane from @eddstrawF1: "Finishing touches are being put on the Red Bull. It will be out this morning - in the next hour, the team hopes."

09:11 Yesterday Red Bull team boss Christian Horner declared that the team's winter build-up had been smoother than ever:

Horner hails Red Bull's 'best winter'

09:12 It's getting slightly warmer: air temperature now 6.7 degrees and track temperature 19.4.

09:14 Rosberg leaves the pits on medium tyres, pausing for a practice start at the end of the pitlane, then works up through the box checking gearchanges, before backing off the throttle.

09:15 The Mercedes trickles slowly through the hairpin and Turns 3, 4 and 5.

09:16 Di Resta sets out from the pits with a 'periscope' measuring device on the car and medium tyres fitted to his Force India.

09:17 De la Rosa's very white HRT sets out, as Raikkonen also rejoins the track.

09:17 Di Resta passes at half speed, Rosberg at full speed.

09:17 Raikkonen is again on medium tyres.

09:18 De la Rosa comes past at racing speed, possibly set for his first flying lap in the HRT.

09:20 Rosberg does a 1m23.207s to go third quickest as he gets the Mercedes up to speed.

09:20 De la Rosa's first flying lap as an HRT driver is a 1m27.243s.

09:21 Raikkonen has done the most running this morning, having started off with a five-lap run averaging 1m20.8s, then a four-lap run averaging 1m21.8s.

09:21 Massa does a 1m24.014s, his fastest lap of the morning so far.

09:22 The Ferrari is on medium tyres, like most drivers so far this morning.

09:22 Massa improves to a 1m23.443s next time around.

09:22 Rosberg goes up to second on a 1m21.918s.

09:23 Di Resta cruises through the pits again, still no quick time from the Force India.

09:23 Rosberg gets his time down to a 1m21.379s, 0.865s behind pacesetter Raikkonen.

09:25 @StrangAutosport: "Kimi looks on it this morning. Taking no prisoners on the apexes and really pushing on to get up to speed."

09:26 @eddstrawF1 also enjoying Raikkonen's comeback so far: "had a watch trackside around the final part of the track. Great to see Kimi leaning on the car. Took a bite of the grass with his front-left entering the pits, so on it on an in-lap. Great to see him back in an F1 car."

09:27 Raikkonen just did a 1m22.250s midway through his third stint of the morning, then on his next lap had a massive lock-up into the final corner and sent tyre smoke billowing.

09:27 Raikkonen does a 1m22.1s, setting consistent times on this run.

09:30 @StrangAutosport with some more Raikkonen analysis: "During his run in the 2010 Renault, two weeks ago, taking into account fuel correction, he was within two tenths of his best lap on his first flyer."

09:30 Ricciardo brings the Toro Rosso back out.

09:32 Ricciardo starts his stint with a 1m25.0s. He set a 1m24.6s earlier.

09:32 Ricciardo improves to 1m23.141s and takes fourth place from Massa.

09:33 Raikkonen returns to the pits after his longest run yet - a nine-lap stint on medium tyres averaging 1m22.5s.

09:34 Ricciardo's Toro Rosso is now the only car out on track. He does a 1m23.9s this time around.

09:35 Ricciardo then improves again, doing a 1m22.578s.

09:37 Ricciardo pits and the track goes quiet again - but only briefly before Rosberg sets off on the medium tyre shod Mercedes.

09:38 Rosberg does another practice start at the end of the pitlane.

09:38 Di Resta comes back out again too.

09:38 Green flag running throughout so far this morning - a serene start to 2012 testing as the new cars show good initial reliability.

09:39 Raikkonen, Rosberg, Kobayashi, Ricciardo, Massa, de la Rosa and di Resta have all set times, though the latter has yet to do a full-speed run.

09:39 Maldonado, Button and Kovalainen have done installation runs but not set times, Webber is yet to emerge at all in the Red Bull.

09:42 Massa has gone back out with the periscope device atop the Ferrari and an old set of mediums, suggesting more calibration work is intended.

09:42 Rosberg zaps past a slow Massa on the straight and then sets a 1m22.597s.

09:42 Kobayashi rejoins on the medium tyres.

09:47 Just Kobayashi on track at the moment, setting a 1m23.454s as he settles in.

09:50 This is one of those mid-morning testing lulls, as Kobayashi circulates alone and improves from mid-1m23s to mid-1m22s.

09:51 A lot of you are emailing live@autosport.com to ask what McLaren's programme is and if all is well as Button has not been out since his installation laps. We're investigating...

09:51 Track temperature has now risen to a cosy 24.4 degrees.

09:52 Raikkonen blasts back out of the pits, and isn't hanging around... He flings it through Turns 3, 4 and 5 even on his out-lap.

09:54 Kobayashi slowed and did laps in 1m25s and 1m27s, then got back down to 1m22.5s.

09:55 Raikkonen sets a new fastest time - a blistering 1m19.670s.

09:56 That's quicker than any time set in Jerez testing last winter, and puts him 1.7s clear of second-placed Rosberg.

09:56 Rosberg comes back out.

09:56 McLaren informs us that Button's absence from the track since the installation laps is just for routine systems checks and the car will rejoin soon.

09:57 That 1m19.6s from Raikkonen was set on medium tyres.

09:57 Rosberg is using soft tyres for this run.

09:57 Raikkonen's next lap through is a 1m20.0s.

09:57 Then he does a 1m20.428s.

09:58 @StrangAutosport reports that Raikkonen was "inch perfect" through the final corner as he went to the top of the times.

09:59 Fellow Lotus men Grosjean and Jerome D'Ambrosio are watching from the pit wall 'prat perch' and getting a masterclass from Raikkonen.

09:59 Rosberg improves his time to 1m21.170s but remains 1.5s down on Raikkonen.

10:00 De la Rosa comes back out in the HRT.

10:00 Raikkonen backs off to a 1m24s on his fourth lap.

10:01 Two hours in, and it's Raikkonen on top with a 1m19.670s, 1.5s ahead of Rosberg, followed by Kobayashi, Ricciardo, Massa and de la Rosa. Di Resta has only set slow times, Maldonado, Button, Kovalainen and Webber yet to get on the board but everyone has been out for at least an installation lap except the Red Bull.

10:01 Kimi pits, and yes he was on mediums! Also for what it is worth he's changed from wearing a red set of driving gloves to a more corporate black pair!

10:02 Ricciardo brings the Toro Rosso back out.

10:04 A new best of the day from de la Rosa, who goes sixth fastest on a 1m26.520s.

10:04 Rosberg shaves 0.008s off his previous best and does a 1m21.162s, but that's still 1.4s off Raikkonen.

10:05 Maybe Rosberg would've been quicker with a year or two's rest from F1...?

10:05 Another improvement from de la Rosa, this time a 1m26.110s.

10:07 Rosberg is back in after a consistent five-lap run all in low to mid 1m21s, averaging 1m21.3s.

10:07 Di Resta stutters the Force India down the pitlane as the Lotus pit wall occupants turn to take a closer look.

10:08 We've just put a poll up on our Facebook page about the look of the 2012 F1 cars, so head over there and have your say.

10:08 Di Resta flies past the pits on what looks like Force India's first proper quick lap of the day.

10:09 The car's attitude through the Turn 3/4/5 section proves this is a flyer.

10:10 Di Resta takes plenty of kerb through Dry Sac and crosses the line with a 1m22.9s to go fifth fastest.

10:10 He presses on into a second lap.

10:11 @TheFifthDriver provides some reassurance for McLaren fans: "For all those asking, @jensonbutton and the team were running some routine systems checks - we'll be on track again shortly!"

10:11 Di Resta improves to 1m22.008s and grabs third.

10:11 The Force India then backs right off.

10:12 Di Resta is 2.3s down on pacesetter Raikkonen and 0.8s off Rosberg, as he slots in just ahead of Kobayashi and Ricciardo.

10:12 Massa comes back out on the same set of medium tyres he has used for the last few evaluation runs.

10:13 Massa now starts a flying lap.

10:14 After that one slow lap - a 1m34s - di Resta is getting back up to speed again, the Force India's rear end twitching through Turns 4 and 5.

10:14 It results in another quick time as the Scot does a 1m21.768s.

10:15 He stays third but gets closer to Rosberg.

10:16 @Lotus_F1Team: "That lap time from Kimi was set on medium compound tyres; it'll be interesting to see how he fares on the softer compounds!"

10:16 Di Resta goes faster still with a 1m21.526s. Impressive stuff from the Scot, who is now within 0.3s of Rosberg.

10:18 Massa does a 1m24.228s on his first flying lap, that's a bit slower than his earlier best.

10:18 Di Resta pits after a stint that started with a 1m22.9s, then a 1m22.0s, then slowing to a 1m34s then banging in a 1m21.7s and a 1m21.5s.

10:19 Massa goes quicker with a 1m23.663s, still 0.3s shy of his previous run.

10:19 A new best of the day from de la Rosa in the HRT - a 1m25.618s.

10:19 Massa and de la Rosa are the only men on track at present.

10:22 Massa is putting some effort in now, he puts two wheels on the exit kerbs at Turn 4, then gets sideways on the exit of Dry Sac, and does a 1m24.111s.

10:23 Rosberg sets out again on what appear to be fresh Pirellis.

10:23 Pacesetter Raikkonen is setting off again.

10:24 Rosberg improves to a 1m20.219s, which puts him just 0.5s behind Raikkonen.

10:25 Rumours are that Red Bull will be going out in the next hour.

10:26 De la Rosa has made another improvement in the 2011 HRT, lapping in 1m25.535s.

10:26 Raikkonen didn't go for a flying lap that time and has come straight back into the pits.

10:27 Rosberg goes by with a 1m21.133s, making good use of his new soft tyres.

10:27 Raikkonen's timing screen topping run was on mediums, though...

10:27 De la Rosa brings last year's HRT back into the pits.

10:28 Kovalainen has now put a second installation lap on the Caterham.

10:28 Raikkonen rejoins and cruises past at half-speed. This is an evaluation run, not a problem for the Lotus.

10:28 Raikkonen and Rosberg currently have the track to themselves.

10:31 Force India update: "just checking each system today and dialling the the car at the same time. Priority is also to get miles today for data collection". Paul di Resta has done 28 laps so far, third fastest 1m21.526s, 1.307s off

10:31 Rosberg is now alone on track and did a 1m21.5s last time by.

10:32 Update from @HRTF1Team: "Back in the garage and Pedro gives his impressions. Balance improved and so has the temperature but there's still a lot of work to do"

10:32 Rosberg comes in and the track falls silent.

10:36 Di Resta exits the pits on medium Pirellis.

10:38 Jenson Button heads out onto the track on a set of mediums too.

10:39 Kovalainen is back out on mediums, and Maldonado takes to the track with an old set bolted on to his Williams.

10:41 Blaz Stremfelj asks how many laps each driver has done so far. Raikkonen, 38; Rosberg, 36; Di Resta, 30; Kobayashi, 14; Ricciardo, 22; Massa, 24; De la Rosa, 17; Kovalainen, 3; Button 2, Maldonado, 3.

10:42 @MikeGascoyne: Heikki just finished another couple of installation laps, now heading out for first proper run. On the hard tyre for the moment

10:43 Button starts a proper run

10:44 Kovalainen and Maldonado on flying laps too.

10:44 Button goes round in 1m23.561s, that's P6. And Ricciardo goes P4 in 1m22.036, his fastest lap of the day.

10:45 Rocky1 asks: “are McLaren and Red Bull playing a cat and mouse game with one waiting to see when the other goes out or what sort of programme the other is running?”

10:47 @eddstrawf1: It's way too early for that. Right now both teams are in the early stages of proving the car. It will be systems tests, checks, gathering baseline data and that kind of thing. What one does can't really influence the programme of the other.

10:47 Kovalainen's first flyer is 1m26.181s. Maldonado goes slowest of all on 1m27.275s.

10:48 Button improves to a 1m22.440s on his second lap. McLaren looking pretty solid so far.

10:48 Maldonado improves by nearly 4s. A am23.547s lap puts him seventh.

10:49 Kovalainen does a 1m24.298s lap, bumping de la Rosa and the old HRT to the bottom of the order.

10:50 Raikkonen rockets out of the pits. From his position near the pit exit, he barely needs to bother with the limiter.

10:50 Kovalainen is back in the pits after a reliable first run for the Caterham.

10:50 Apologies, Button is on soft tyres, not mediums. Easily noticeable at slow speed as he trickles past the pits on a slow lap.

10:51 The 2009 world champion is back in the pits now and is immediatley surrounded by mechanics and photographers. He's P6 at the moment, 2.7s off Raikkonen's pace-setting time.

10:54 Ah. The moment you've all been waiting for as Red Bull's RB8 takes to the track for the first time. It's Mark Webber at the wheel today.

10:57 Massa on a couple of flying laps currently. The Ferrari driver's latest is 1m25.208, over a second off his best.

10:58 Ricciardo leaves the pits again, practicing a start as he does so.

10:59 Krishna asks: “Last year there were issues with marbles during testing. How are the Pirellis behaving this year, do we have as much marbling as last year?”

11:00 @eddstrawF1: "It doesn’t appear that we have anything approaching the marbles that we had in testing last year. That’s not a big surprise as Pirelli put a lot of work into reducing the marbles. As you say, the early tests and races last year produced a hell of a lot of rubber off line, but that reduced as the season goes on. Off-line, from the parts of the track I have watched at, there’s no problem."

11:02 Massa goes past the pits working on an evaluation process, and that sums up a morning where we've seen nothing to suggest a good, hard run yet from the Ferrari man. Track temperature now up to 28.9 C.

11:06 By way of a meaningless comparison, the fastest time on the first day of last year's Jerez test was a 1m20.709s by Massa. Fastest today so far is Raikkonen in 1m19.670s. Don't read too much into that though.

11:07 Ricciardo has the track to himself as Massa pits. But Rosberg looks like he's about to take to the track in his Mercedes. A set of softs on his machine.

11:11 Di Resta takes his Force India out of the pits. It was here at Jerez a couple of years ago that he first made a big impression on the team at the first young driver test.

11:13 Brendan has a question about the new nose regulations: “We’ve heard the lower nose is to stop cars from going over the top of another, such as Mark Webber in Valencia in 2010. But having a lower nose, wouldn’t that create a 'submarining' problem with a car going under another? Remember the Schumacher/Liuzzi crash in Abu Dhabi in 2010...

11:14 @eddstrawf1: "It’s a fair point. In fact, in this week’s AUTOSPORT magazine Gary Anderson comments on that exact point in our eight-page analysis of F1 2012. Inevitably, if you lower the nose to stop cars being launchdd, you can have the opposite effect, so there is a balance to be struck there. You make a very good point about the Abu Dhabi crash, and that was one of the case studies that the FIA looked very closely at during the process. However, it’s worth noting that, although it was close to hitting Schumacher in the head, he was in the clear thanks to the height of the cockpit. That will have been taken into account."

11:17 Visit our Facebook page and have your say about the appearance of 2012's breed of F1 cars.

11:19 Webber puts in the first 'proper' lap for a Red Bull this year. 1m23.556s puts him only ninth. There'll be a couple of teams quite happy to freeze the order right now.

11:20 Webber heads a gaggle of cars into the pits. Raikkonen is in too, so Ricciardo has the circuit to himself.

11:24 Ricciardo makes full use of the clear track to set his best time of the day in 1m20.694s. He can't improve on his third spot though

11:25 After trying out red gloves earlier, Raikkonen is back to black now. They do go with his overalls better, after all...

11:27 @ToroRossoSpy No official lunchbreak in Jerez, but at 12.30 Dan has done 34 laps in the new car and is currently 3rd fastest. All going ok so far

11:30 Webber, following that earlier run, is in the pits in his Red Bull. Looks rather nice from above, doesn't it? The Australian has the car for today and tomorrow before Sebastian Vettel takes over for Thursday and Friday's running.

11:30 Massa is back on track and on medium tyres. Kobayashi's Sauber joins him.

11:32 McLaren reports that Button's run ticked all the boxes this morning. The British driver did a big systems check after the initial installation lap and hopes to do some longer runs this afternoon.

11:32 Ferrari is not concerned with times and is happy with the progress made on its programme.

11:33 Williams says everything is running to plan and that normal progress is being made for a new car.

11:34 Ricciardo pits, ending his longest run of the day. He's been out for 11 laps. The Toro Rosso driver is still third quickest.

11:36 Rosberg makes another practice start as he leaves the pits. De la Rosa follows the German out, but doesn't bother laying the rubber.

11:37 Button goes back onto the track in his McLaren, and a massive tank-slapper as he accelerates out of Curva Michelin and down through Turn 3.

11:38 It's a lesser-spotted Williams today; Maldonado having managed just eight laps so far. He's on-track right now though.

11:41 Massa reaches the 40-lap mark in his Ferrari. Nothing spectacular from the Brazilian today, who lies seventh on the timesheets. Ferrari is, as usual in testing, running the odd-looking periscope on his car. All in the name of data collection.

11:42 Massa's still some way off Rosberg though on the laps completed chart. The German racks up 51 tours today before pitting.

11:43 Button's McLaren looks very slow past the pits... False alarm. He was just backing off. No problem by the looks of it as he picks up speed through the opening sequence of corners.

11:45 Maldonado sets his best time of the day in 1m23.371. It's an improvement of less than a tenth, though, and keeps the Williams man in eighth.

11:45 Kobayashi and di Resta head back onto the track.

11:46 @redbullracing We were late getting out today because of the delayed arrival of some components due to heavy fog! We're all systems go now though

11:46 Well, that clears that one up then. No issues with the new RB8.

11:48 Holy banjo. Di Resta improves by 1.2s to go third in his Force India. Just Raikkonen and Rosberg ahead of him. That's Renault engine leading two Mercdes powerplants and two Ferraris.

11:48 De la Rosa has the hard compound Pirellis on as his HRT leaves the pits

11:49 Soft tyres for Rosberg as he heads back out, and once again does a practice start.

11:51 Kovalainen and Caterham are off the bottom of the timesheets. The Finn does a 1m23.178s lap to go eighth. Over 1.1s quicker than his previous best - which was set on only his second flying lap of the day.

11:52 Maldonado and Di Resta are both back into the pits.

11:53 Joachim Othman asks:  "What does HRT get out of testing the 2011 car? I can understand that they can test the new tyres, but for a relatively poor team, wouldn't it be better to spend money on developing the new car?"

11:55 @eddstrawf1: "A fair question, and it's worth noting that HRT is only doing two of the four days here partly for that reason. There is a certain amount that you can learn. As you point out, the main thing is getting on top of the new Pirellis, and in the case of Mercedes, which is also running its 2011 car, that will be the main priority. But HRT is in an unusual situation. Not only is Pedro de la Rosa new to the team, but the changes in terms of personnel and the way it has been run over the winter mean that all concerned will benefit from a couple of operational days on track. The idea would be that come the Barcelona test, the team will have its 2012 car ready to go after passing its crash tests. So it should allow the team to hit the ground running when the new car is on track for the first time."

11:56 Kovalainen pits too. Just Rosberg and de la Rosa are on the track at the moment.

11:58 The pair pit, so it's all quiet... for about 15 seconds. The Sauber mechanics fire up the C31 and out goes Kobayashi. Di Resta follows him out on mediums.

11:59 @MyCaterhamF1 Heading towards the lunch break and Heikki's 18 laps in, best time so far of 1.23.178.

12:00 @eddstrawf1: Just saw Daniel Ricciardo patiently posing with his ever-present grin for photos with some local fans.

12:00 Massa heads out on mediums. That periscope looks like it will be a permanent fixture to his Ferrari today.

12:04 Toro Rosso team boss Franz Tost reckons Caterham now has the package it needs to join the midfield fight. Red Bull KERS will, he thinks, provide a big step forward. Watch this space...

12:06 Well Caterham certainly has looked okay today. Only four tenths of Ferrari so far, so could be a good year for Norfolk - or a bad one for Maranello. Very early days though...

12:06 Massa comes down pitlane, but doesn't stop at his garage. Instead there's another practice starts.

12:08 Button is back out in his McLaren. The Mercedes engine sounds glorious!!!

12:09 Massa repeats the practice start trick as de la Rosa heads back out.

12:12 And another practice start for Massa. First gear on that F2012 is getting a serious workout today!

12:15 So halfway through the day, Raikkonen is quickest. Find out more about the man who has given him such a (seemingly) quick car by reading Jonathan Noble's interview with Lotus technical director James Allison.

12:16 Webber is out on track, and gets his Red Bull very sideways out of Turn 3.

12:17 The Australian is pushing that RB8 hard.... 1m21.474s puts him up to fifth. The car works then.

12:18 Panic in the Jerez press room as there's a power cut! AUTOSPORT's intrepid reporter Sam Tremayne is sent to resolve the problem... and it works! Not before several laptops shut down and a few more swear words are heard though.

12:18 There won't be any Lotus machinery on track for a little while - the team has broken for lunch.

12:19 @AlanPermane: An excellent first morning in Jerez for us. 50 untroubled Laps. Small break for lunch, a couple of changes and then more of the same please!

12:20 That'll be the Lotus trackside operations director feeling pretty pleased with the team's morning then.

12:23 Kobayashi thrashing around on his own in the Sauber, now four laps into his run. 1m22.164s on his last lap, about 0.6s off his best lap of the morning.

12:24 Kovalainen is back on track - which is now 31.7 C. That's an improvement of just under three degrees in the last 90 minutes.

12:26 @InsideFerrari: The first part of today's job has been completed without any issue on the car. yfrog.com/nvjq0lj

12:27 @InsideFerrari: Felipe completed a total of 51 laps , the quickest in 1.22.815.

12:27 One imagines that Ferrari has now broken for lunch, as there's no sign of Massa's car in the pits or on the track.

12:30 Kovalainen blasts past the pits to begin a hot lap... and really maximises the kerbs on the exit of Turn 5. That's the Curva Sito Pons for those of you with an interest in two-wheeled GP history - named after the man who won the 250cc world titles in 1988 and '89 world titles. A very big name in these parts.

12:30 Kovalainen does back-to-back laps in 1m24.760s and 1m24.838s. That's pretty consistent from the Finn.

12:31 Maldonado is the only other man on the track and completes his lap in 1m25.042s.

12:32 The Venezuelan has flames spitting out of the right exhaust of his Renault-engined Williams FW34 as he negotiates turns four and five. 1m23.944s is 0.6s slower than he's managed today.

12:32 Six more laps in the bag, and Kovalainen returns to the pits.

12:35 Maldonado continues on-track and does another high 1m23s.

12:35 Hasn't everyone been well-behaved today. Not a single red flag. Come to think of it, not a single yellow either...

12:36 Looks like most of the teams are having lunch at the moment. Sauber isn't though as Kobayashi is sent out for another run.

12:37 Salil has a question about location: "Why is Jerez chosen as a Testing venue when not all teams are based in Spain?"

12:39 @eddstrawF1 (working overtime today): "Definitely, it's a bit of a trek from the UK (where the majority of the teams are based) to Jerez. But having encountered scenes equivalent to Rally Sweden on my journey to the airport a few years ago and had a hefty flight delay because of snow and ice, staying close to home at, say, Silverstone isn't really an option at this time of year. While only HRT is based in Spain, the country's southern Europe conditions are significantly warmer. Right now it's around 15C (air temp), which is about 15 degrees warmer than it would be in the UK. It's a similar story in France and Germany, where you are likely to encounter very cold weather, rain and even ice/snow. Jerez is close enough to be easy to get to without being so far away as to be too expensive or time-consuming to travel to. It's also a pretty good test track, albeit not quite as good as Barcelona, so it works well."

12:46 Webber back onto the track in his Red Bull. Medium tyres fitted.

12:47 Daniel Pettit asks: "Why are Red Bull happy to spend a couple of hours of their precious testing time sitting in the garage. I'd have thought that the cars would be good to go for their first installation laps the moment the track opened, or - as two teams did - for a shakedown during a 'filming day'. Also, how many of the drivers who aren't running today are at the track to see how it is going?"

12:50 @eddstrawF1 (we do keep him busy...): "Red Bull certainly planned to be up and running straight away, but given the tight schedules it's not a surprise that the odd team falls a bit behind. They had the engine fired up pretty early and the schedule was likely to get going as soon as possible. It's likely that they just fell a little behind because of the fog that prevented some parts arriving on time. As for the drivers who aren't running, plenty of them are around. Both Romain Grosjean and Jerome d'Ambrosio are around at Lotus, Williams tester Valtteri Bottas is here and they aren't the only ones. Some of the less experienced ones in particular like to keep an eye on things to learn."

12:51 Webber reaches nearly 169mph on the back straight on that lap, but doesn't improve his lap time. Too little rear wing perhaps?

12:54 Webber has done eight laps so far on this run - his longest of the day. Interesting that the paint job on the RB8 really masks the step in the nose. The Australian is sixth at the moment, but only needs to find 15 hundredths to move ahead of Sauber driver Kobayashi

12:57 @tonyfernandes Good start to caterham as a formula 1 team. Long way to go. But there is promise in the car. Heikki gave me some positive feedback. Very early days but reasonable start.

12:57 Webber pits and that means the track is empty. Don't want to tempt fate but - whisper it - the AUTOSPORT crew might just get some lunch today!

13:00 Typical. Spoke too soon. Engine noise emanates from the pits and a quick glance reveals it's Kobayashi San, heading back out in his Sauber.

13:01 There's a banner out in one of the stands for Pedro de la Rosa. "Go, Pedro go. You'll never race alone," it reads. Wonder if that's Jerez's answer to The Kop...

13:03 Find out what went on this morning at Jerez in our handy wrap-up, and keep tabs on what happens for the rest of the day right here on AUTOSPORT.com.

13:05 And remember, you can ask us about any of the burning topics going on in F1 by email us on live@autosport.com.

13:07 @Lotus_F1Team: Lunch at Jerez and a chance to welcome our new @Lotus_F1Team fans; we reached 70k followers today, thanks for your support! #F1 #GreatFans

13:09 Kobayashi is showing great consistency on this run. After a 1m21.542s on his first lap out of the pits, he's gone 22.6, 22.9, 22.7 and 22.5 before returning to the pits.

13:11 Come to think of it, doesn't the livery on that Sauber look an awful lot like the one used by the Epsilon team in Formula Renault 3.5 in 2010?

13:12 @clubforce Lunch time in Jerez and @Jules_Bianchi is doing some interviews

13:13 Lunchtime is a bit of a loose term here in Jerez, as there isn't an official on-track break. Instead, the teams have chosen to take their breaks as and when seems suitable. And with that, the place goes quiet again.

13:15 More details on the Red Bull delay in taking to the track this morning. @eddstrawF1 has been down there and found out that the plane carrying the RB8's rear wing assembly was unable to land at Jerez airport due to fog, and was diverted to Seville - about two hours away - instead.

13:17 Eric Boullier looks a very relaxed man as he wanders out to the pitwall. He has every reason to be as well, his driver Kimi Raikkonen's 1m19.670s lap has Lotus on top of the timesheets.

13:21 @RobertDoornboss GO ICEMAN!!!!

13:23 And we have our first sight of Pirelli's supersofts in 2012. This set is bolted on to Kobayashi's Sauber - get ready for a quick lap. Wonder if the team's sponsors have just arrived...

13:24 How inspiring. It's an installation lap for the Japanese racer as he pits... and then goes straight back out again.

13:25 Some Finnish guy in a black car goes onto the track... Raikkonen. Yes, that's his name. And he's not messing about either as he scythes through Expo and up to Michelin (so nice to have corner names, rather than numbers here).

13:26 Funnily enough, Pirelli's press release from yesterday says there will be no supersofts at Jerez. Somebody's had their felt tips out then...

13:26 Di Resta heads out on mediums.

13:30 A (kind of) pitstop for Raikkonen. No teamwork or tyre changes, but he pulls into his pit bay and, after a quick moment stationary, pulls away and trundles back down the pitlane.

13:37 The top two on the timesheets are out on track right now. Raikkonen's Lotus is just ahead of di Resta's Force India at the chicane in this shot, and just 0.102s clear of him on the timesheets too.

13:40 @eddstrawf1 has been down to Toro Rosso. The team reports a satisfactory debut of the STR7, with Ricciardo getting through plenty of laps and reporting no problems. The car has been out on the hard tyre only with the usual first day jobs of data acquisition and system checking being undertaken.

13:40 Di Resta and Kobayashi are still pounding around the circuit. A total of 122 laps completed between them so far.

13:42 Kobayashi goes straight through the pits and back out again.

13:43 @karunchandhok F1 2012 is go...sort of...today's times more meaningless than even the rest of test days but wonder who'll chase the 'glory times'

13:46 Sir Frank Williams reckons the FW34 will be the start of a new era for his eponymous team. What do you reckon? Go to our Facebook page and have your say.

13:47 After a short stint in the pits, Raikkonen is back out on the track. And after a far longer spell out of the car, Button follows the Finn out in his McLaren.

13:51 And Ricciardo heads out on medium tyres for the first time today. At last, several cars on-track at the same time.

13:52 Button sets his best time of the day in 1m21.952s. It's four tenths quicker than he's managed so far, but doesn't move him up from seventh.

13:53 Webber returns to the track for Red Bull... as Sam Michael ventures out to the McLaren pitwall with a cup of tea. Very strange to see Sam in anything other than Williams gear...

13:54 And McLaren's sporting director is chatting to the team's technical director Paddy Lowe. Unconfirmed reports that Lowe is more of a coffee man himself.

13:55 @karunchandhok nice to see Kimi back at a proper test... Watching him attack Becketts at Silverstone in 2003 is still a standout memory for me!

13:57 For the stattos among you, Karun was racing in the British F3 national class that year and was part of a three-way title fight that went to the season finale with Steven Kane and (champion) Ernesto Viso. Bit of an ugly crash at Brands Hatch decided that one, if I remember rightly.

13:58 A roar in the pitlane announces the arrival of Michael Schumacher, who has assumed driving duties for Mercedes for the final few hours of on-track action today.

13:59 Button passes Ricciardo out on the circuit, although he is still a place behind the Australian on the timesheets.

13:59 Another car comes in, and goes straight back out again. A common trend today. This time it's Webber, who exits the pits just ahead of Button.

14:00 A few corner behind them there's Schumacher and Ricciardo barely feet apart too.

14:00 Button passes Webber, but lets the McLaren man repass at Michelin.... and then pits.

14:06 Webber still out on track, and while we're talking Red Bull, you might like to know that Christian Klien, who scored points on Red Bull's grand prix debut in Australia in 2005, is 29 today. Coupled with that tweet from @RobertDoornboss earlier, this is turning into a serious Red Bull retrofest. Tonio Liuzzi, we're wating...

14:06 Schumacher pits and makes, you guessed it, a practice start.

14:07 The German is bottom of the timesheets right now. Don't expect that to last though.

14:08 Raikkonen's had another quick stop in the pits, and is back out, as are Kobayashi and Massa - complete with olbligatory periscope.

14:08 @HRTF1Team Lunch break but track action doesn't stop. RAI is fastest (1'19.670) and Pedro runs P11 (1'24.209/32L) aboard the F111

14:09 Why spoil the sequence. A fourth outlap-box-outlap in as many tours for Schumacher.

14:11 Bhargav Radhakrishna asks for more pictures from today's test. Your wish is our command Bhargav. Check out our test gallery, which we will, of course, be adding to until Friday.

14:13 Did I say four times for Schumacher? Make that five.

14:14 This time Schumacher pits properly, as does Massa. Just Kobayashi left on-track now.

14:15 Massa and di Resta head back out onto the track.

14:24 In case you were wondering, the AUTOSPORT team is hard at work in the Jerez press room, braving powercuts and possible starvation (damn the lack of a lunch break). Here's the team. Introducing, from left to right; Sam Tremayne, @eddstrawF1, @NobleF1 and @StrangAutosport.

14:26 @Lotus_F1Team The #E20 glistens in the sun as Kimi brings it home from another solid run #Raikkonen #Iceman #F1 yfrog.com/h4nssnjj

14:27 @eddstrawF1 reports that Caterham has KERS fitted, but is only in passive mode today.

14:29 More like it from Webber. His best time of the day as he laps in 1m20.917s. P5 for the Red Bull driver.

14:30 Massa and Ricciardo go out on mediums as Jenson Button watches the action from the pitwall. He seems to be paying special attention to the Red Bull (go figure) and the Force India (the dark horse for the season perhaps...).

14:31 Schumacher heads onto the track as Ricciardo comes in - and goes back out.

14:32 @karunchandhok: Lots of tweets ref car designs which reminds of what a top designer once told me - there are no right & wrong designs... just fast & slow ones

14:33 My goodness. Schumacher stays out on track this time...

14:33 ..and goes quicker than so far today, a 1m20.794s puts him fifth.

14:34 The Mercedes set new personal bests in all three sectors, and registered massive straightline speed at the end of the lap.

14:35 A 1m21.4s for Schumacher to follow that.

14:36 Di Resta takes his tally up to 84 laps for the day - not a bad effort, as he edges past previous benchmark Kobayashi's 81.

14:36 That's lap 15 on this run for the Force India, which started out in mid-1m24s and is now doing mid-1m25s.

14:38 First red flag of the day.

14:38 Ricciardo's Toro Rosso has stopped at Curva Expo, the first turn.

14:38 The Australian was going slowly down the main straight before having to park the car.

14:39 Impressive that the teams got nearly seven hours into the first day of testing their largely untried machines before red flags were required.

14:41 Recovery trucks head down towards Turn 1, where the Toro Rosso lies.

14:41 It had looked like Ricciardo might try and limp right round the lap, but instead the Toro Rosso had to limply park.

14:42 Ricciardo is out of the car with his helmet off, and has a small army of photographers lined up by the barrier.

14:42 The tow truck has lifted the Toro Rosso onto its back with minimum of fuss.

14:43 Until it came to actually lowering it...

14:43 The marshals can't quite decide which way around the car should be placed, so it's currently just spinning around...

14:44 Success! The car is down on the truck.

14:45 While we're paused, time to announce our first special guest of our 2012 Live testing coverage.

14:46 New Williams driver Bruno Senna will be joining us on AUTOSPORT Live to answer your questions tomorrow. So email live@autosport.com with any queries you want to put to him about 2012, Williams or any other topic.

14:47 The safety car peels off. As Ricciardo stopped at the pit exit, it won't be a long trip home.

14:48 Nifty work from the Toro Rosso mechanics, who have the car sheeted up before the low loader passes rivals' garages.

14:48 Some red flag reading for you all - technical analysis of the new Force India, Sauber, Toro Rosso and Lotus on AUTOSPORT Plus.

14:50 Back to green.

14:50 Button first out, his McLaren shod with medium Pirelli rubber.

14:50 Kamui Kobayashi's Sauber follows suit.

14:52 STR remains tight-lipped about the nature of Ricciardo's problem despite the best efforts of our intrepid team.

14:52 Webber now also out, and like the McLaren and Sauber, the Red Bull is on medium compound tyres.

14:53 Remember Nick Heidfeld, the man who this time last year was about to successfully audition for the Renault seat left vacant by Robert Kubica's horrific injuries? Here's what he's up to now:

Q & A: Heidfeld on his Rebellion sportscar deal

14:53 Lots of action in the McLaren garage, and sure enough Button dives into the pits.

14:56 Red Bull looks good again in the technical sections - Webber records the highest top speed of any car today through sector two.

14:57 He's started his run with a 1m21.6s lap, 0.7s down on his earlier best.

14:58 Massa heads back out again.

14:59 Webber continues this run with a 1m21.8s.

15:00 Button goes back out too, while after a heavy morning of running, Raikkonen and Lotus have been quiet this afternoon.

15:01 Kobayashi comes across for a 1m24.996s as the clock ticks down and we move into the final hour of the opening day of testing.

15:02 So for your 4pm recap: Raikkonen remains quickest on a 1m19.670s, a tenth ahead of di Resta, with Rosberg, Ricciardo, Schumacher, Webber, Kobayashi, Button, Massa, Kovalainen, Maldonado and de la Rosa completing the order.

15:02 Everyone is using 2012 cars except Mercedes and HRT, and Mercedes is the only team that switched drivers at lunchtime.

15:03 In the mileage charts, Kobayashi has notched up the highest tally with 89 laps, just ahead of di Resta on 86, while Massa has done 67 and Raikkonen 63.

15:04 Button immediately puts in a new personal best time of 1m21.530s, quicker than before in all three sectors but still 1.8s off the outright pace.

15:05 Lowest mileage of the day is unsurprisingly Schumacher, as he only took over the Mercedes from Rosberg at lunchtime, while of the 'all day' drivers Maldonado and de la Rosa have only done 25 and 32 laps respectively - though de la Rosa is going back out now.

15:05 Massa dives into the pitlane.

15:05 Schumacher heads out to try and increase that modest lap tally.

15:07 Toro Rosso is unsure whether its car will be able to go back out again today after Ricciardo's recent issue.

15:08 Here are Adrian Newey's early thoughts on Red Bull's competitiveness:

Newey unsure about RB8's speed

15:09 And this is what Kovalainen is thinking about the new Caterham:

Kovalainen sure CT01 a step forward

15:10 Kobayashi is up to lap 12 of a long run, lapping mainly in mid-1m26s.

15:10 De la Rosa pits, leaving Button, Kobayashi and Schumacher out on track.

15:11 Button is onto lap six of his run. After kicking off with a 1m21.5s, he has now drifted up to high 1m22s.

15:11 A reminder that Bruno Senna is our special guest on AUTOSPORT Live tomorrow morning, so send any questions you have for him to live@autosport.com.

15:13 Caterham news from @MikeGascoyne: "Testing finished for the day unfortunately. No problem with the car but a damaged starter shaft means we can't start it"

15:14 @MikeGascoyne adds: "shame as was a really positive day up till then"

15:15 When testing has finished in 45 minutes - or during test if you fancy multi-tasking - head to our Facebook page and have your say about the new cars' looks.

15:15 Kobayashi ends a 23-lap run and pits.

15:15 While Button and Schumacher are both regularly in the 1m22s.

15:20 News from @ToroRossoSpy on Ricciardo's issues: "Car suffered a drop in oil pressure and the engine protection system shut it down. Nothing serious but not enough time to fix it before 5pm"

15:21 Di Resta, our veteran of 86 laps today, heads back out on medium compound tyres.

15:21 The Force India will keep Button company as the McLaren was the last car left on track for a while.

15:22 Button is now on lap 15 of this long run and notching up consistent mid-1m23s.

15:22 Kobayashi heads out for Sauber.

15:23 Throw in early in/out laps and this is Button's 20th, and of his flying laps only one has gone over 1m24s.

15:24 Webber hits the track with medium tyres on his Red Bull.

15:25 Button pits, having averaged 1m22.9s on that long run.

15:27 Nice little wriggle for di Resta as he gets a dose of understeer on the run from Michelin down to Turn 3.

15:28 Webber improves his best time of the day to a 1m20.496s - fourth place - on his first flying lap of his medium tyre run.

15:29 And though Webber only clocked a 1m28.0s next time, his speed in sector one topped 300 km/h - the fastest seen all day. Unexplored potential?

15:30 Massa and Schumacher head back out to keep Webber and Kobayashi company.

15:31 Massa only did an out/in lap and has pitted.

15:33 Webber has pitted too.

15:33 The Sauber has stopped at the back of the circuit, another red flag is imminent.

15:33 As the red comes out, Kobayashi has already hopped out of the car and removed the headrest.

15:34 The Sauber has stopped on the long back straight heading down to the Dry Sac corner.

15:35 The safety car is already at the scene, along with a marshal whose fire extinguisher is thankfully superfluous on this occasion.

15:36 While there's nothing happening on track, have a think about what you might want to ask Williams driver Bruno Senna. He's our special guest on AUTOSPORT Live tomorrow, and you can email your questions to live@autosport.com.

15:36 Spanish efficiency: a low loader is now alongside the Sauber and already the car is being lifted away. Plenty of marshals and personnel at the scene.

15:37 Again the covers go on the car - two Sauber team members making sure their secrets are covered before the car returns to the pits.

15:37 More red flag reading material coming up for AUTOSPORT Plus subscribers...

15:38 Tony Dodgins examines whether this year's technical rule tweaks will close the field up:

How ugly rules could hurt Red Bull

15:39 @eddstrawF1 finds out from Sauber how to make a successful F1 car on a budget:

Making a successful budget F1 car

15:39 Marshals not being quite so efficient getting the car on...

15:40 The car is finally on the truck and the covers are pulled back over it.

15:42 With the Sauber loaded up, the truck returns to the pits with three safety cars in tow.

15:42 @eddstrawF1 informs us that Kobayashi had run out of fuel.

15:43 That's unlikely to be an oversight by Sauber - teams often deliberately run dry during winter testing as part of planned consumption tests.

15:44 Red Bull boss Christian Horner and team manager Jonathan Wheatley have headed down to the last corner to watch proceedings.

15:45 The truck carrying the Sauber gets back and the session resumes.

15:45 Just 15 minutes left for anyone to try and deny Raikkonen a glorious timesheet-topping comeback day.

15:46 Raikkonen is actually first man out, followed by de la Rosa, Button and Schumacher.

15:47 Earlier we were puzzled by Sauber appearing to use super soft tyres, which aren't in Pirelli's selection this week. Turns out they were hard tyres painted red.

15:47 Webber is the latest to join the fray.

15:50 No sign of supersonic times in this final flurry of laps just yet.

15:55 Trackside news from @StrangAutosport: "Kimi looking super smooth into final corner. Button and Webber running together - both cars already looking planted under braking"

15:55 Raikkonen has a massive lock-up on the brakes into the final turn as he comes round to set a 1m26.302s.

15:56 Button's turn to lock up into the final corner as he is chased by Webber.

15:56 Both Button and Webber are lapping in mid-1m22s, Raikkonen in 1m25s and 1m26s.

15:59 Heading into the final minutes, unless anyone bursts out for a one-lap quali-style sprint now, it looks like Raikkonen and Lotus have day one bragging rights.

16:00 Final minute and de la Rosa sets a new personal best, but still 4s down on Raikkonen.

16:00 The chequered flag is out.

16:00 Button dives down the inside of Raikkonen at the Michelin curve.

16:01 That's it for day one of pre-season Formula 1 testing in 2012.

16:01 It will be remembered as the day Raikkonen said "remember me?" by beating last year's best Jerez testing time before the day had barely begun - and then stayed on top till the finish.

16:02 Second place goes to di Resta in the new Force India, followed by Rosberg in last year's Mercedes.

16:02 The new Red Bull was fourth with Webber, while the McLaren of Button and Ferrari of Massa were a quiet eighth and ninth.

16:03 Kobayashi may have caused a late red flag when his Sauber ran out of fuel, but he still notched up the day's top lap count with 106. Di Resta was next up on 101.

16:03 But just 25 laps for Maldonado in the new Williams.

16:03 Testing doesn't always tell an accurate picture - remember last year Rubens Barrichello's Williams was fastest of all during the Jerez week, a dizzy height the car never came near approaching when the actual season started.

16:04 But nevertheless, Raikkonen's performance this morning - with his best time set on medium tyres, not softs - will have erased many doubts about his return with Lotus.

16:04 AUTOSPORT Live resumes just before 9am Jerez time tomorrow morning for coverage of day two.

16:04 Bruno Senna will be our special guest, so email any questions you have for the new Williams driver to live@autosport.com.

16:05 We hope you enjoyed our coverage of the opening day of Jerez action and look forward to more of the same tomorrow.