Hello and welcome to the first session of practice for the Spanish Grand Prix. The cars will be out on track in just under 15 minutes.
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The picture below is from yesterday, it's actually a little cloudy out there and there was rain over night.

As always if you have any questions or want to make any observations, you can send them to me by clicking here. I'll try to post as many as possible throughout the session.

The drivers are settling into their cars, we should have the installation laps underway any minute now. Michael Schumacher is climbing into his newly revised Mercedes with its rather unusual airbox and longer wheelbase.

The track is fairly cold so they'll have to work their tyres pretty hard to get the necessary heat into them. Liuzzi completes two laps and passes a number of cars on the way, but is now heading back to the pits.

Eliat from Taipei says: "I wonder whether the longer wheelbase chasis is confined to Schumacher's, or also to Rosberg's car. Would be interesting to see if it is beneficial to Schumacher and at the expense of Rosberg."

It's an interesting point. Both cars are running the longer wheelbases as it is benficial to rear tyre wear. They have managed to shift the weight distribution backwards and in doing so stop the rear tyres spinning up. Whether it helps one driver more than the other will only be obvious in qualifying.

All the drivers have now completed at least one installation lap to check their car's systems are running correctly.

"Just wondering about the potential of increased wheel sizes in the future. Why would the teams and everyone involved (excluding tyre companies) not want to use a larger wheel with a smaller profile tyre when they always keep going on about road applications of f1 technology?" asks Jake.

The latest reports in the German press say Michelin are happy not to use 18 inch wheels but nothing is certain yet. The teams are a little reluctant as they will have to re-think their 2011 chassis designs if the tyre formula does change. Ultimately it will be another expense that the teams don't want with the ban on double diffusers and the possible introduction of KERS. The most important thing is that a solution is found sooner rather than later.

Right, back to the action - no flying laps yet but Glock and Hulkenberg are out on track. As I type, Hulkenberg dives back into the pits travels straight through and heads back onto the track.

Vettel - complete with a new haircut - is out of his car. Red Bull are in no rush this morning.

Ferrari explains why there is a lack of action: "There will be some time to wait before the drivers will run again. With only one set of tyres available it is useless to run too early."

Weather update from Renault: "Humidity is still relatively high at 64 but it is sunny out there now." Things are brightening up.

Neville from South Africa says: "Once Michael is running his confidence level will be fairly obvious. If he hustles the car around he's back!"

I'll try my best to relay to you how is driving when he gets out on a hot lap.

Ferrari is testing its F-duct with Massa out on the track at the moment. Rob Smedly is briefing Massa over the radio on how and when to use it.

De la Rosa spins but it's not serious and he gets going again. He lost the rear end under braking for the slow turn 10.

Reports that a bargeboard fell off Glock's car. I didn't see it myself but that would be a bit worrying if true.

"I believe F1 run 13 inch tyres because it allows for higher tyre profile. The suspension configuration does not allow for much suspension travel which is basically found in the high tyre walls," from Neville.

Yep, spot on. But the teams have said they could adapt to 18 inch wheels. It would just require a little bit more work and, crucially, more money.

"Will the Spanish fans warm to Lewis and show him some respect this year? Can they forgive the past?" Interesting question from P. Dowding.

I can't say for sure, but there has been no sign of any problems this year. If anybody is in Spain with the fans and wants to add to this, please get in touch by clicking here.

So Massa is quickest on a 1:23.386, some 8 seconds faster than Klien in the HRT. Klien is driving for the team on Fridays now to add a bit of experience to the line-up.

There is Burger King sponsorship on the Sauber this weekend, good to see some extra cashflow there.

Laura from Barcelona says: "I haven't been to the circuit yet, but I don't think Alonso's fans have forgotten. Anyways Spanish F1 fans are different, and some of them do really love the sport, like myself. I hope the fans behave this year!"

Update from Mercedes: "Installations runs completed for Michael and Nico now... both drivers out of their cars at the moment"

Timo Glock heading back to the pits after a 8 lap run. Virgin says: "Timo due in this lap. He'll be doing some checks to set the clutch bite point in the pit lane."

A question from Al: "What are the chances of having split Q1 qualification at Monaco?? Read that some drivers are pushing for a split Quali because of such a difference in speeds between the top cars, and the end group."

Some drivers are keen but no word from the FIA. On safety grounds it is probably a good idea but we're not quite sure exactly how the session would be split.

Webber out on track now, setting a flying lap time. He's third fastest, Kobayashi in the Sauber is fastest with a 1:23.190 but it's still a bit early to be reading anything into these times.

Kobayashi goes even quicker with a 1:22.492, Mark Webber is 0.493 off in second place now.

Paul di Resta is out on track in the Force India, subbing in for Adrian Sutil this weekend. He's 7th fastest 1.141 seconds off the pace. Force India says: "Paul out for his first true run of the day, still on the primes he will do six laps"

Schumacher is out on track now, I'll keep an eye on his progress but don't expect to get a full understanding of how those Mercedes updates stack up until qualifying.

Trulli says the Lotus feels better now with its updates for this race, including a new front wing.

Webber and Vettel are now topping the timesheets in the Red Bulls, Webber quickest with a 1:22.011.

Schumacher is now fifth fastest, 0.701 off Webber's time.

Button is about to set his first lap time of the day, Hamilton is also out on track. Button 6th fastest 1.094s off Webber. Webber and Vettel are now back in the pits.

Alonso is also out there and about to set his first lap time. Schumacher sets the fastest lap with a 1:21.716.

Schumacher, Button and Hamilton are the three fastest drivers on track at the moment.

Button goes quickest with a 1:21.672, just 0.044 faster than Schumacher.

Hamilton has now put in the fastest lap as a replay of Rosberg shows him off the track at turn 2. No obvious damage and he's kept the car going, bouncing through the gravel trap.

Hamilton's best lap time of 1:21.134 is faster than the lap record but only laps set druing the race count towards setting a new one. But considering this is first practice and they are on hard tyres, I suspect we will see a new lap record on Sunday towards the end of the race.

Update from Renault: "Robert reports some understeer especially on high speed, he's now working with his engineer on the set up and balance of the car."

Alonso and Massa are lapping 1 and 2 seconds off the pace respectively. But that is quite normal for Ferrari on Friday, don't expect to see a really fast time from them until Saturday.

Vettel understeers off the tarck at turn 10. No damage done (it's a concrete run-off there) but he is obviously pushing quite hard.

Jakes adds his thoughts on the prospect of 18-inch tyres next year: "I understand the concept of a smaller wheel thereby allowing the suspension to do a smaller/finer job and let the tyre absorb half(ish) the forces, but for 'real world' application, 13inch wheels have no relevance. For the purpose of design of the car, yes, I would imagine the suspension would definitely need serious redesign, but it is simply another item that will be absorbed in the bi annual sweeping rule/aero changes that seem to happen! As long as f1 doesn't adopt anything like the hideous Deltawing IndyCar monstrosity!"

Alex from Russia asks: "Is there any news about Kimi Raikkonen coming back to Formula One?"

Only rumours, certainly nothing solid. He seems quite happy in rallying and says he enjoys the relaxed atmosphere there. He's also starting to score points so I wouldn't be surprised if he just stuck with that.

Lewis Hamilton, still the fastest driver so far, is studying data in his car. Meanwhile, Webber, Rosberg, Petrov, di Resta, Massa, Barrichello and Glock are out on track.

Ferrari preparing Alonso's car for F-duct analysis: "The crew is working on Fernando's car to prepare it for a back-to-back test of the rear wing ... and the same will happen to Felipe's car."

The sun is coming out now and the track is now warming up a bit.

Di Grassi holds a huge slide into turn one but still ends up in the gravel. Keeps his car going and pops back onto the track.

A small mistake from Hamilton sees him run wide in the turn 8 chicane. He holds it together well, but it won't do anything for his lap time.

Button has run over a piece of carbon fibre coming out of the pit lane and is now out of the car and back in the pits.

Barrichello seems to have some kind of oil pressure problem, the rear of the car is off in the garage. De la Rosa has a gearbox failure and won't come back out in this session.

Button also out for the rest of this session after he ran over something coming out of the pit lane. He has damage to the rear of his car.

Hulkenberg has stopped on track at turn 6, it looks like an engine problem.

Massa and Alonso are fastest through the speed trap, a sign that Ferrari's F-duct is working well. Their lap times aren't as impressive though, with Alonso 8th and Massa 12th.

Schumacher has only completed 9 laps so far but is still third fastest. As I type, Schumacher heads back out on the track.

Webber is lapping 5 seconds off the pace and is likely on a very heavy fuel load.

Barrichello is back out on track as the Ferraris go out again without an F-duct.

All cars are out on track except de la Rosa. Button has got his car back out despite the damage to the rear.

Schumacher returns to the pits without setting a better time.

Chequered flag is out but nobody looks likely to beat Hamilton's time.

So Hamilton (1:21.134) is fastest ahead of Button (1:21.672), Schumacher (1:21.716), Webber (1:22.011), Vettel (1:22.026), Rosberg (1:22.070), Kubica (1:22.202) and Alonso (1:22.258)

Thank you for joining us, be sure to come back for second practice when the picture of the weekend should unfold a little more as drivers use the soft compound tyre and continue their set-up work.