Bruno Senna rounds the final corner © Sutton

04:45 Hello everyone and welcome to AUTOSPORT Live as we begin coverage of the second day of action at the 2010 Petronas Malaysian Grand Prix.

The teams have had two 90-minute practice sessions to tune the machinery to this tricky and challenging 5.543 km Sepang F1 Circuit.

Before the action gets underway, we will look back on the Friday practice sessions, update you on the latest weather at the circuit and look at some of the finer details to emerge from an interesting first day at Sepang.

04:46 Today, we will guide you through the final practice session with minute-by-minute commentary as the teams and drivers begin their build-up to qualifying.

Third practice will begin shortly, with commentary ending 15 minutes after the session has concluded.

Later, at 07:45 GMT, we will return for live coverage of the all-important qualifying session and the battle for pole position.

We will wrap up the day, after qualifying, with a detailed look at the thunderstorm situation around the circuit and the all-important prospects for Sunday on the Malaysian Grand Prix Weather page.

Lewis Hamilton topped Friday's sessions © Sutton

04:47 Lewis Hamilton put down a marker in practice after his disastrous race in Melbourne last weekend. The McLaren star topped both sessions of free practice, taking the limelight away from the teams that have set the pace so far this season - Red Bull and Ferrari.

The McLaren MP4-25 looked supreme as Hamilton and team-mate Jenson Button powered their way to the top of the order in the morning. Nico Rosberg did well to split the British duo in the final minute of the session, pushing team-mate Michael Schumacher down to fourth.

Formula 1 debutant Fariuz Fauzy enjoyed his outing in the Lotus T127, replacing Heikki Kovalainen, and the Malaysian provided most of the off-track entertainment - twice coming unstuck at the quick Turns 11 and 12 sweepers.

Hamilton leads opening Sepang practice

The afternoon provided a perfect case study into how a racing team goes about its preparation for the event. There would be plenty of evidence regarding who was quick versus who wasn't, but you had to look beyond single-lap pace to understand exactly what was going on.

Hamilton once again proved he had the outright speed, as he lapped the circuit in 1m34.175s. But during the second half of the session the teams turned their attention to race fuel loads. Consequently the lap times dropped off by around four seconds per lap for much of the time.

Behind Hamilton came Vettel, Rosberg, Button and Schumacher. The gap between them was less than 0.5 seconds which bodes well for a close and exciting qualifying battle later today.

Hamilton fastest again in second practice

04:49 Saturday dawned fine and dry above Sepang. There are some clouds around but nothing to be concerned about just yet.

The airport radar is now showing shower activity building quickly to the east. We will be keeping a very close eye on the situation for you throughout the day.

While it remains dry, the maximum temperature is up to 32 degrees Celsius with a track temperature reaching its peak at 48 degrees.

Fans in the stands at Sepang © Sutton

04:50 AUTOSPORT forum members are invited to join the fun throughout the weekend, offering thoughts and opinions as the event unfolds.

Our questions to you this afternoon are:

• Ferrari has yet to show itself at the top of the order this weekend, but its drivers clearly spent much of yesterday running race-related fuel levels. Will Massa and Alonso be back up the order this morning?

• McLaren's F-duct is undoubtedly helping this weekend in terms of top speed, while allowing the team to put more downforce on the car for the twisty first sector. Will Hamilton and Button lock out the front row in qualifying or can Red Bull's undoubted single lap pace put its drivers on top again?

• Thunderstorms could feature to make an already interesting weekend even more dramatic. Do you want to see showers or storms during qualifying or the race?

Tell everyone what you think.

Click the SHOW LIVE FORUM link in the red bar at the bottom of your browser window if you would like to join the debate.

Vitaly Petrov had problems with his R30 © Sutton

04:51 Some news in brief as we go into Saturday:

• Jenson Button and Nico Hulkenberg both fell foul of the pitlane speed limit during Friday practice. The world champion was clocked at 62.3 km/h during the second session, resulting in a 600 Euro fine. Hulkenberg was caught doing 61 km/h and received a 200 Euro fine for his misdemeanor.

• Mark Webber was forced out of second practice yesterday with a Renault engine failure. The Australian lost almost an hour of available track time, but was quick to rule out the significance of the breakdown as the unit had already put in a lot of mileage.

• Webber pulled off the circuit at Turn 9 and the marshals recovered his stricken RB6 from the gravel. During this time, Nico Rosberg and Jaime Alguersuari both set quick second sector times while yellow flags were displayed. The FIA stewards looked at both instances after the session and subsequently decided: "that the driver took the appropriate action and no breach of regulation occurred."

• Vitaly Petrov was another driver to suffer reliability issues during practice. A fuel pump problem sidelined the Russian after just nine laps in the morning. The afternoon went much better, but towards the end of the session the team discovered a water leak on the R30.

Graining rear tyres on the Lotus © Sutton

04:53 Sepang's challenging corners and fierce heat gave the tyres a lot to think about as the drivers tested long-run pace on each compound choice yesterday.

Heavy graining was in evidence throughout the field, often on the right rear and particularly on the softer option rubber, leaving drivers to complain about instability at the rear as the patch of moving rubber rolled across the tyre surface.

Whether the teams will get a chance to run long stints on Sunday very much depends on the volatile climate failing to provide the almost inevitable afternoon thunder showers. However, the interest for today will be in the close performance on one lap pace between the two compounds, likely because the harder rubber can be warmed quickly on such a hot track surface.

"The hot temperatures should mean that there is a clear difference in durability between the two compounds, however the best laptimes should be quite close because the heat assists the warm-up of the higher temperature range hard tyre. This will make strategy considerations interesting and we could see some variety in the tyre used by the Q3 runners tomorrow," said Bridgestone's Hirohide Hamashima.

04:55 There are five minutes to go until the final practice session begins.

04:56 Under increasingly cloudy skies, the track temperature is a hot 46 Celsius with a 31 degree ambient.

04:57 The temperatures for both track and air will continue to drop away slightly as the clouds build above the circuit.

04:59 Bruno Senna is ready to roll and will be one of the first out onto the circuit this afternoon.

0 min: The practice session is underway.

0 min: The Lotus pair lead the field out of the pitlane.

0 min: Sebastien Buemi and Karun Chandhok join the Lotus drivers on the circuit.

1 min: Mike Gascoyne passes on the weather prospects from Meteo France: "Forecast saying no rain for next 30 mins"

1 min: The teams are immediately sending drivers out, as Alguersuari, Vettel, Hulkenberg, Liuzzi, Senna and Webber all head out.

2 min: Trulli and Kovalainen trundle down the pitlane after a single tour as others continue installation laps.

2 min: Adrian Sutil comes out in the Force India, as the first batch of drivers return to the pits at the end of the installation lap.

3 min: Fernando Alonso completes his installation lap, with team-mate Massa out at the moment.

3 min: Rubens Barrichello joins the racetrack. The Mercedes drivers have yet to roll out today.

4 min: Lewis Hamilton is now out for a tour round in his McLaren.

4 min: Along the pitlane, the downloading of data is in full swing with most drivers now back in the garage following that installation lap.

5 min: Once the telemetry engineers are happy that everything is okay, the drivers will be given the all-clear to go through the work for this session.

6 min: Lucas di Grassi waits patiently in his Virgin car as the team check for problems after his lap around the circuit.

6 min: Sebastien Buemi reports on the Toro Rosso team radio that he had very little braking efficiency on that lap.

7 min: The Virgin team is testing a new fuel pickup system this morning in an attempt to solve a problem with getting good fuel supply on low tanks

7 min: Buemi adds that he could feel a vibration under braking and had to apply an abnormal amount of pressure to get the car slowed down.

7 min: Michael Schumacher has been out and back into the pits for his checking lap. Nico Rosberg is the only driver yet to run.

10 min: Timo Glock has jumped out of his Virgin while one of the mechanics work on some adjustments around his seat.

10 min: Pedro de la Rosa is sent out on the track with the suggestion to get on with it as thunder showers continue to build to the east.

12 min: De la Rosa crosses the line and is on to the first flying lap of the session.

12 min: Mark Webber heads out onto the track for his first run of the day. The Australian lost a lot of track time yesterday with that engine failure.

13 min: Tonio Liuzzi also goes out in the Force India. The teams are concerned about some showers in the area.

13 min: De la Rosa sets the ball rolling with a 1m36.891s as the first laptime of the day.

14 min: Webber is immediately quick and posts 1m34.920s, taking the quickest time away from de la Rosa.

15 min: Felipe Masa is heading out with the harder tyres on his Ferrari.

16 min: Webber is faster still on his second lap but he slows in the final sector so he can have another crack at a quick lap.

16 min: The track temperature has dipped to 42 Celsius as patches of cloud build overhead.

17 min: Tonio Liuzzi is now second to Webber with a time of 1m36.524s.

17 min: De la Rosa is now third quickest, with team-mate Kobayashi fourth and di Grassi fifth in the Virgin.

17 min: Sebastian Vettel takes the quickest time away from Webber with a 1m34.714s as the pace hots up at Sepang.

18 min: Alonso is also testing the harder tyres on his Ferrari and he beats the early times from the Red Bull pair with a 1m34.678s.

19 min: The order is Alonso, from Vettel, Webber, Massa, Liuzzi and de la Rosa after 19 minutes.

19 min: Felipe Massa is now fourth quickest with a 1m35.196s and currently following Kubica's Renault.

20 min: The McLaren pair are warming up for their first flying laps of the day.

20 min: Michael Schumacher is out on track and about to start his first flying lap today in the Mercedes.

20 min: Nico Rosberg finally joins the racetrack. The German is the only driver not to have completed an installation lap so far.

21 min: It is possible that Rosberg will go straight into a run of laps.

21 min: Hamilton is just a tenth off Alonso's pace by the end of the second sector on his first flying lap.

22 min: Hamilton goes second to Alonso and just a fraction down after a quick F-duct aided run through the final sector.

22 min: Michael Schumacher is about to edge into the top ten on his first flying lap, as Buemi goes sixth with a 1m35.258s.

22 min: Button slots in fifth quickest with his first effort, six tenths off the pace.

23 min: Schumacher does much more than edge into the top ten. A stunning final sector time helps him to third place with 1m34.711s.

23 min: Hamilton has now cleared Petrov and Rosberg and is back in clear air.

24 min: Robert Kubica clocks his best time to go 10th quickest.

24 min: Sebastian Vettel and Mark Webber are both back in the pits following a short run of laps. They are fourth and fifth currently.

25 min: Hamilton is immediately setting the pace now he is free of traffic. It isn't a perfect lap but is quick - 1m34.029s.

26 min: Nico Rosberg shoots into the top seven with a time of 1m35.102s.

26 min: Button sets his best time of the session at a 1m34.749s but remains sixth.

26 min: Rosberg is likely to improve on his next effort ... but he backs off towards the end of the lap and will have another go at a clear lap.

27 min: Vitaly Petrov has a major moment in his Renault at Turn 6, losing the rear, putting him off over the gravel on the outside.

27 min: Adrian Sutil has only completed three laps thus far. He is on track now with a set of soft tyres bolted onto the Force India.

28 min: Button is told on the radio that rain could arrive in five minutes so he is to pit for a run on the softer tyres.

28 min: Sutil completes his first effort in 1m35.306s and in now in the top ten.

28 min: Petrov has returned to the Renault pit after that major off-track moment.

30 min: Problems for Sebastian Vettel at Red Bull. During his first run we saw what looked like a piece of rubbish wrapped round his front left wheel.

The piece detached but it appears to have caused some damage to Vettel's left front corner. The mechanics are now looking at the problem.

30 min: Most of the cars are in the pits, pondering how to manage the threat of rain from a rapidly-developing thunder cell.

30 min: Sutil moves up three places to seventh position with a time of 1m35.029s as he continues on a soft tyre run in the Force India.

31 min: The airport radar shows us that a short, sharp shower could hit the circuit very soon.

32 min: McLaren has gone with its plan of a move to the softer rubber to get a lap in before any rain arrives.

32 min: Hamilton is immediately quickest through the first sector.

33 min: He is two tenths up on his own benchmark by the end of the second sector and on for an improved time.

33 min: Blasting down the final straight and around the final corner, Hamilton improves the leading time to a rapid 1m33.559s on the softer tyres.

34 min: Jaime Alguersuari is 15th in the classification at the moment but is set to improve on this current lap.

34 min: Jenson Button can't match his team-mate and slots in second quickest, over half a second slower.

34 min: Alguersuari leaps up to seventh position with a time of 1m35.026s in the Toro Rosso.

35 min: His team-mate Sebastien Buemi is also very fast and moves up to fourth place on a 1m34.673s.

35 min: Odd spots of rain are now falling at the circuit, with a shower moving very close to the track.

36 min: Nico Hulkenberg improves to tenth place in the Williams, with a lap of 1m35.067s.

36 min: The teams are scrambling to get some laps in before rain impacts the grip levels.

36 min: Alonso improves to a 1m34.207s to take third quickest.

37 min: Hamilton's next flyer is a couple of tenths down on his pacesetting time.

37 min: The order up front is Hamilton leading with 1m33.559s ahead of Button, Alonso, Buemi, Schumacher, Vettel and Webber with 22 minutes to go.

39 min: The McLaren pair pit after a pre-qualifying blast on the softer rubber, while many continue to lap on the harder tyres.

40 min: The immediate threat of rain is over for the time being. The latest shower on the radar passed just a couple of miles to the south.

40 min: Alonso edges closer to the McLaren pair with a 1m32.127s, a few laps in to his run on used hard rubber.

41 min: Michael Schumacher has moved up a place to second in the Mercedes. His time was 1m33.992s, as team-mate Rosberg goes third with 1m34.090s.

43 min: Sebastian Vettel jumps up to seventh spot with a time of 1m34.397s. He is now one place ahead of team-mate Webber.

43 min: Glock is now on top of the battle of the new teams after a recent 1m37.299s in his Virgin, despite a moment clattering over the kerbs.

45 min: Kubica pits his Renault to wrap up a stint on the harder rubber.

47 min: The bulk of the field is in the pits currently as the drivers request changes ahead of a final run on the circuit in the final ten minutes.

50 min: Webber, Buemi, Sutil and Alguersuari are all on the track for a final run. They occupy positions eighth to 11th at the moment.

50 min: Alonso and Massa are out for a run on the softer tyres, which should provide an interesting indication of qualifying pace.

52 min: The local radar tells us that the rest of the session will be clear of rain. 100 km to the east, however, big storms are building.

52 min: McLaren and Mercedes did their soft tyre laps earlier on during the threat of rain, so won't have fresh tyres for this late blast.

52 min: Alonso is the quickest man through the first sector and is just fractions down on Hamilton by the end of the second segment.

53 min: Alonso completes his flyer in 1m34.024s after a poor final sector where he encountered Petrov's Renault.

53 min: Mark Webber is up to second place behind Hamilton with a lap of 1m33.630s. The pack is closing down on the Briton's time.

54 min: Massa's soft tyre effort is slower than his earlier best and he remains seventh.

56 min: Replays show an aerodynamic part falling off Kovalainen's Lotus as the late scramble for times continues.

56 min: Webber is continuing to attack the circuit in the RB6. He posts the quickest second sector time of all and will challenge for P1 on this lap.

56 min: Webber just snatches the top position away from Hamilton with a lap of 1m33.542s.

57 min: Hamilton is unable to improve on his times on used soft tyres.

57 min: Sebastian Vettel is also on the move and set to move towards the top to join team-mate Webber. He goes third with 1m33.587s.

57 min: The top three drivers - Webber, Hamilton and Vettel - are covered by just 0.045s.

60 min: Ferrari isn't entirely happy with that late outing: "not the perfect run for both drivers with soft tyres"

06:00 The flag is out to end practice in Malaysia.

06:01 There are no major improvements during the course of those final laps from the drivers.

06:02 Mark Webber takes the honours at the end of final practice at Sepang with a lap time of 1m33.542s. Lewis Hamilton was second by just 0.017s.

06:02 Kobayashi and Glock just beat the flag and are still trailing back to the pits.

06:03 Sebastian Vettel makes it two Red Bulls in the top three, with Fernando Alonso fourth and Michael Schumacher in fifth place.

06:04 Nico Rosberg finishes one-tenth of a second down on his team-mate in sixth position, with Jenson Button in seventh spot.

06:05 Felipe Massa was eighth in the second Ferrari. Rubens Barrichello put in a good lap early in his final run for ninth place, with Kubica rounding out the top ten.

06:06 Here's our round-up of an interesting final practice hour:

Webber edges Hamilton in practice

06:08 Sepang dodged another shower as Mark Webber wrestled the top position away from the man of the weekend so far - Lewis Hamilton.

Sebastian Vettel's late run to third place means the three of them are covered by less than one-tenth, setting us up for a brilliant qualifying session.

Join us for full coverage of the shower-threatened qualifying shootout from 07:45 GMT.