Hello again, and welcome to first practice for the Chinese Grand Prix. Following on from Malaysia, these are our first back-to-back races of the season, and the big question is can anyone stop Sebastian Vettel? Having won the first two races of 2011, he's already 24 points clear in the drivers' championship...

McLaren took another step closer to the front-running Red Bull last weekend, but can they keep closing the gap? Red Bull have a 'significant upgrade' planned for this race, so we'll be keeping a keen eye on what improvement it brings.

Mercedes and Ferrari are both looking to improve on disappointing starts to their respective seasons, and it's not all about the front of the grid either. HRT will be looking to get more mileage on its car after finally qualifying for a race in Malaysia, and Lotus will be hoping to close up to the very tight midfield once again.

Now, depending on where you are in the world it could be very early or very late. Whatever time it is, we want to hear from you, so get in touch via Twitter @ESPNF1_live

Before the session starts, the driver changes for this first session are as follows: Toro Rosso have Daniel Ricciardo in for Jaime Alguersuari, Nico Hulkenberg is in for Adrian Sutil at Force India, while Lotus have replaced Jarno Trulli with Luis Razia.

And the session is underway in a muggy Shanghai. Lots of guys getting out to do an installation lap early.

A few chassis changes have been needed for this weekend too: Vitaly Petrov has a new one for Renault after his late crash in Malaysia, and Sergio Perez also requires a change of chassis after hitting some loose Toro Rosso ballast early in the race.

Michael Schumacher carries out a practice start from the end of the pitlane and heads out on to the track. Only Vettel, Hamilton, Petrov and Kovalainen have let to go out and do an installation lap.

Jenson Button has done two installation laps, and we've just seen him carrying out an engine performance check on the main straight. McLaren are running an updated floor this morning.

imvoxian on Twitter says: "There's nothing to do so I'm gonna check the comments about @Formula1 Chinese Grand Prix P1 on @ESPNF1_live :) #ILikeF1"

So that means we need to see some comments from you; can you see Red Bull being beaten? And would you like a race with high tyre degradation again like Malaysia, or less pit stops like Melbourne?

I was about to tell you Lewis Hamilton was going to set the first flying lap of the session, but then he runs wide at the hairpin at the end of the back straight and pits.

Heikki Kovalainen is the only man on track now, and the last one to complete an installation lap. Only McLaren have completed two. That's as exciting as it gets so far.

Nico Rosberg heads out for Mercedes, he has the track to himself. Mike Gascoyne looks very tired today for Lotus, as he was stuck in a taxi for four hours last night when his driver got lost trying to get him to his hotel from the airport. It's not all glamour.

Rosberg is back in the pits, so we are still yet to see a lap time set. D'Ambrosio goes out in the Virgin and Karthikeyan in the HRT so maybe that will change...

Another driver change I had missed (and now amended) is Hulkenberg in for Sutil at Force India.

Narain Karthikeyan comes through to set the first lap time of the session, a 1:51.516. He's fastest, obviously.

imvoxian again on Twitter: "I think will be the European season until we can see if McLaren or Ferrari will be ready to beat Red Bull."

The European part of the season starts in Turkey in three weeks time.

Kamui Kobayashi completes a lap in 1:45.609. Karthikeyan has improved to a 1:48.0, 0.9s quicker than his team-mate Liuzzi.

Expect these times to drop quickly. And as I say that, Lewis Hamilton goes over three seconds quicker with a 1:42.306 and Jenson Button then second on a 1:43.442

Teams have got an extra set of hard tyres to use across the two practice sessions today. The plan is to allow them plenty of time to set up the cars without wasting tyres, and then the tyres are handed back tonight.

Jenson Button improves to a 1:41.835, the quickest time so far. Hamilton's going quicker though...

And Hamilton goes faster again with a 1:41.0.

Felipe Massa is third quickest ahead of Mark Webber. Seven cars on track at the moment on a hazy morning.

Webber jumps to the top of the timesheets with a 1:40.692, 0.15s quicker than Hamilton.

Red Bull's KERS is again the subject of much interest, and Christian Horner confirms it is on both cars for this session as he hopes for "a problem free weekend with it". He also says that the system is less of a factor off the line here than it was in Malaysia, but the lap time gain means they hope to run it all weekend.

Mark Webber goes quickest in all three sectors and does a 1:40.055.

Another correction for you: Luis Razia is in for Jarno Trulli, but Heikki Kovalainen has not been replaced by Davide Valsecchi. Just the one change for Lotus today.

Red Bull have just told Mark Webber not to use KERS on his next timed lap, which could be a comparison test or could be more gremlins.

Sebastian Vettel runs wide at turn six. He's currently 11th quickest, but don't read in to times this early too much. As I say that, Vettel goes third on a 1:40.922.

Vettel is wrestling with his RB7 out on track, struggling with the dusty circuit.

Luis Razia is touring around with a damaged Lotus. The front left half of his wing has broken off and dropped underneath the car, while his left front steering arm is also broken. Jarno Trulli in the garage does not look impressed.

Ferrari wheel Fernando Alonso back in to the garage, sporting a front wing covered in high visibility aero paint as they analyse airflow.

Vettel has improved to within 0.15s of his team-mate, while Perez moves up to fifth place.

Vettel is the first man under the 1m40s barrier, setting a 1:39.540.

All of the drivers can use the DRS whenever they like during practice and qualifying, but in the race the zone has been marked out as a section of the long back straight that leads in to a hairpin.

Only Alonso, Glock and Heidfeld have yet to set a time today, although Barrichello's 2m04s was hardly a flying lap.

Everyone has been running the hard tyre so far in this session. Soft tyres are at a premium ahead of qualifying and the race, as Hamilton well knows; he flat-spotted a pair of soft tyres in Malaysia which meant he couldn't use them in the race.

Michael Schumacher really struggling to get his Mercedes to turn in when he wants it to at the moment, plenty of understeer for him on the still very dusty track.

Lotus say that a "small suspension problem" caused the front wing failure on Razia's car, as Hamilton has a big moment in turns seven and eight with the car snapping away from him and running wide.

The busiest two men so far are Massa and Maldonado with 14 and 13 laps respectively.

Schumacher radios in to say that his rear tyres are going off after nine laps, soon followed by evidence as he slides out of turn three.

Vettel improves at the top to a 1:38.739. That's over 1.3s quicker than anyone else.

Glock and Heidfeld have only done two laps so far, but Heidfeld is now on track in the Renault.

Button radios in to say that the KERS system is not working on his McLaren, and the team respond saying it needs to cool down. Red Bull not the only team having issues.

Heidfeld sets his first timed lap, going seventh with a 1:41.4.

Heidfeld improves to fifth, as Button runs very wide at the last corner. Daniel Ricciardo also goes wide at turn one.

Nick Heidfeld has gone off and hit the wall on the run down to turn 11, taking the front wing off his Renault.

Heidfeld was sat in the car for quite a while trying to select first gear to bring the car back, but was unable to and now he steps out. Replays show that he took too much kerb on the outside of turn 10 and spun.

Paul Di Resta takes a bit too much speed in to turn one and spins, but manages to keep the car just out of the gravel.

Not a huge turnout in China so far today it is fair to say.

Narain Karthikeyan passes the few fans in the main grandstand © Getty Images

Mark Webber has improved to a 1:39.354. We've got nine cars on track at the moment.

Ferrari on Twitter say: "Fernando has left the garage now for his first proper run."

Towards the back of the grid, Liuzzi in the HRT is quicker than Razia after his problem, and within 0.3s of D'Ambrosio's Virgin. Timo Glock is yet to set a time.

Alonso's first lap has put him in 18th behind Michael Schumacher. Webber and Hamilton are on track now too.

Alonso now jumps up to ninth, making full use of his DRS around the lap.

Nick Heidfeld admits "It was just a mistake...I lost the car." He also said he is surprised to be fifth at the moment as he didn't feel the car was handling very well.

Pastor Maldonado has spun between turns seven and eight, and his car is perched on the kerb with his rear wheels spinning. He's had to switch the engine off.

On board replays show Maldonado was sliding for a while through turn seven and managed to slow the car down before completing the spin, then let the car roll out of the way before selecting first gear to find it was beached.

Ten minutes to go and both Red Bulls and McLarens are out on track. The front-running teams are busy with Massa having done 23 laps and Webber completing 22.

Heidfeld's Renault is returned to the paddock on the back of a truck. It took marshalls a while to move Maldonado's car though, in fact they're still doing so which means the yellow flags are still out preventing fast times.

Hamilton locks up his tyres braking for the pit lane limiter line. Could be a speeding fine on the way as well as some damaged tyres.

Kovalainen has got a fine for speeding in the pit lane earlier in the session, leaving him 2,400 Euros out of pocket.

Karthikeyan locks up his front left tyre as he brakes for the hairpin towards the end of the lap and runs wide.

A busy circuit now, with 17 cars on track.

Paul Di Resta crosses the line just as the chequered flag drops.

Anyone who crossed the line just before the end of the session will have had their final laps ruined though, as Tonio Liuzzi pulls off on the inside of turn two having run wide at the last corner.

Vettel returns to the pits for a practice pit stop as the quickest man, a 1:38.739 putting him 0.6 seconds ahead of his team-mate Mark Webber. Hamilton is third another 1.5s back, ahead of Button, Heidfeld and Massa.

McLaren will have been testing new parts though, so that gap to Red Bull may not be a true one. Not a great session for Heidfeld or Maldonado after their spins, but they'll hope to get more time in the afternoon session. Join us for that in two and a half hours.