2009 Malaysian Grand Prix Race day at Sepang

Jenson Button leads the field round the back of the circuit, and onto the Penang straight as they begin the turn for home.

Robert Kubica worryingly reports very strange noises from his BMW engine.

The field are initially led away at a leisurely pace, before picking up speed after the first complex of corners.

The formation lap is underway at a hot and sultry Sepang F1 Circuit. All 20 drivers leave the grid without problem.

The softer tyres are the choice of the field for the start.

The engines begin to fire with a minute before the formation lap.

The BBC report that Button's front wing had to be changed due to problems with the new-for-2009 adjustable front wing system.

The drivers are ready to race. Jarno Trulli closes his eyes and focuses on the job he has to do this afternoon from second on the grid.

There are now five minutes remaining until the formation lap begins in Malaysia.

On the rain radar front, a line of showers is still evident and continuing to approach the circuit.

The teams will be monitoring the Formula 1 weather pages very closely at this time, as they consider the various weather possibilities.

Right now, the sun is moving between the clouds and still showing through from time to time. But in the distance, we can see dark clouds moving closer to the track.

The drivers are getting in to their cars with eight minutes to go before the formation lap.

The Brawn team have made a late change of front nose on the pole sitting car of Jenson Button.

There is a lot of tension on the grid as the teams prepare to react to any sudden changes in the weather.

Bernie Ecclestone is touring the grid with a VIP party that includes the Malaysian Prime Minister.

The spectators rise to their feet as the Malaysian national anthem rings out over the Sepang circuit.

The pits are now closed. All 20 cars are on the dummy grid.

Felipe Massa, starting fro 16th place today, is standing by the guardrail with a damp towel round his neck to keep cool, as he is involved in deep conversation with his race engineer Rob Smedley.

Conditions have become fully overcast again in the last few minutes.

Jenson Button's Brawn GP team think the expected rain will arrive at 5pm local time - just as the race starts.

Red Bull designer Adrian Newey is taking a walk down the grid, and appears to be very interested in the shape of the Toyota TF109, as he passes Timo Glock.

Sebastien Buemi makes his way round the track towards the grid with the softer tyre on his Toro Rosso STR 5. The Swiss driver is starting from 20th position this afternoon.

The drivers are beginning to arrive on the dummy grid ahead of today's race. Some will slow down and then immediately light up the tyres to ascertain grip level. Some simply roll slowly towards the grid. The marshals will then take over in most cases, and push the car into its grid slot.

The track temperature is 38 Celsius, in a 30 degree ambient. The current hazy sunshine and patchy cloud cover is holding back the asphalt temperature from reaching the peaks of earlier in the weekend.

The softer tyre is being used for most of the reconnaissance laps. This gives the drivers a breif opportunity to check the performance of the rubber following the rain since qualifying that will have changed the grip levels significantly.

Jenson Button is on his reconnaissance lap towards the grid. He is another to go round on the softer tyre, as Jarno Trulli joins the racetrack some way behind him.

Nico Rosberg also has the soft tyre bolted onto his Williams.

Lewis Hamilton pulls out of the McLaren garage with the softer tyre on his car.

Nick Heidfeld comes out of the pits, and is making his way round to the grid on soft tyres.

Timo Glock is ready in his Toyota, waiting for the signal by his team to leave the garage.

The pits are now open for the cars to make a reconnaissance lap to the grid.

A cultural display of dancing on the grid has been entertaining the crowd in the massive main grandstand in the build up to the start.

The local performers have now cleared off the grid, with the mechanics now wheeling out their trolleys of equipment. Today they have to be ready for any sudden downpours, as rain continues to be a significant threat.

The pitlane will be open in ten minutes for the cars to make their way around to the grid.

The drivers will be interested to find out how much grip they have, especially in the slow-speed sections of the track.

The all-new KERS (Kinetic Energy Recovery System) continues to be a talking point here in Malaysia, with the long straights meaning the potential of the technology to improve car performance can be fully demonstrated.

So far, only four teams have decided to run their KERS during the grand prix. They are:

Scuderia Ferrari
Felipe Massa
Kimi Raikkonen

McLaren Mercedes
Lewis Hamilton
Heikki Kovalainen

BMW Sauber
Nick Heidfeld

Renault F1
Fernando Alonso
Nelson Piquet

Once again, only one BMW will run the KERS system in today's grand prix, with Robert Kubica forced to run without the device due to his weight.

Weather conditions have brightened slightly in the last 30 minutes, but further showers remain a high possibility before the end of the race.

The Malaysian rainfall radar currently paints a gloomy picture, with showers advancing westwards, towards Sepang from the east.

If the rain stays away from the circuit, the early laps of the race will still provide action, as the drivers battle the handling of their cars on a green, slippery track.

Wet tyres

Bridgestone is providing four different dry-weather rubber compounds during the year and is bringing a pair of tyre options to each race.

For Malaysia, the hard and soft compounds are available to the teams, with the latter marked by a green band on the sidewall.

Practice has shown the soft tyre to be particularly suited to this track, and it has been delivering both a fast initial lap from new and good consistency over a run of laps.

This morning's shower may, however, have upset that trend with the majority of the racing rubber having been washed from the asphalt surface.

Should rain intervene in the race, the teams have an ample supply of intermediate and full wet tyres on hand. None of the running so far this weekend has been rain affected, despite the showers hovering just beyond the track.

Earlier today, the spectators were treated to a very wet GP2 Asia race, eventually won by Vitaly Petrov.

Next on track was the Formula BMW Pacific race for ten laps around the 5.543 km circuit, which was by that point almost dry again after that earlier shower.

Most recently, the Formula 1 drivers' parade took place, with the fans getting their first chance today to cheer on their heroes.

Jenson Button will line up from pole position with a 660kg Brawn GP Mercedes, according to the list of car weights released by the FIA. The top ten drivers seem to have similar plans for the first stint of the race, with weights only differing by a few kilos.

Sebastian Vettel did have a lighter Red Bull to take third quickest time in Q3, but his ten-place penalty for that collision with Kubica in Australia means he will start deep in the pack on a light fuel load.

Nick Heidfeld's BMW, the pair of McLarens and Felipe Massa's Ferrari all tip the scales at around 690kg and are clearly planning a long first stint as they battle to move out of the second half of the grid.

Post-qualifying car weights - Malaysia

BMW Sauber lodged a protest after qualifying on Saturday against the controversial double-decker diffuser designs used by three rival teams.

The protest against the Brawn GP, Toyota and Williams cars, which all qualified strongly on Saturday, has been rejected - meaning the diffuser saga will be decided at the FIA International Court of Appeal hearing on April 14.

Stewards reject BMW Sauber's protest

Jenson Button

Final practice and qualifying produced a tight grid with many subsequent talking points on Saturday.

Nico Rosberg topped the early practice session for Williams, ahead of Mark Webber - showing well in the Red Bull RB5. Felipe Massa and then the two Toyotas of Jarno Trulli and Timo Glock were next in the final classification. It was one of the closest ever practice sessions, with all 20 drivers covered by just 1.4 seconds.

Rosberg fastest again in final practice

The qualifying session turned out to be thrilling, with a few shocks along the way.

Felipe Massa and Ferrari committed a cardinal sin, by allowing themselves to believe they would be safe from elimination in Q1. With such a tight field, the simple truth is that no-one is safe from being dropped these days. Massa was forced out as other drivers went faster on their final lap in the first period.

The McLarens fell at the next hurdle. The MP4-24 is undoubtedly showing some signs of improvement, but as yet does not have the pace to break into the top ten. Up front, Jenson Button once again stole the show. He starts today's race from his second straight pole position in the Brawn, with the Toyotas of Jarno Trulli and Timo Glock surrounding him at the start.

Button grabs second consecutive pole

This morning the skies were bright with no hint of what would follow a short while later. Earlier this afternoon, a heavy downpour soaked the circuit, prompting fears of a wet race.

Since then, the track has dried out very well in the fierce heat, but further showers are likely in the next few hours.

The maximum temperature today will reach 31 degrees Celsius, but with plenty of cloud cover the track temperatures will be pegged back somewhat compared with the earlier track sessions.