Malaysia Practice 3: Rosberg again on top

Nico Rosberg was fastest again in final practice

(GMM) Both Brawn runners had a worryingly smoky final practice session at Sepang on Saturday afternoon, but the team insists it remains on track.

"It's just that we're running maximum oil level," engineer Jock Clear, alluding to engine overfill, told a concerned Rubens Barrichello during the session.

The Brazilian completed the session without problem and ninth quickest, and teammate Jenson Button was tenth, the Briton having also reported "a big puff" of white smoke from his customer Mercedes at the exit of a corner.

Engine failures this year do not attract penalties until a driver has run through eight power plants, but a problem in round two would put the Brawn pair behind schedule for the season.

Williams' Nico Rosberg finished the practice session fastest, for the fifth time out of the six practice sessions so far in 2009.

Runners for Red Bull, Ferrari and Toyota were also in the top seven, but the two McLarens and Renaults continued their struggle for pace.

Melbourne winner Button believes Ferrari is the favorite to win on Sunday.

"You might think I'm crazy or that I'm trying to talk us down but I think that Ferrari are the team to beat at this moment," said the Brawn driver.

McLaren mechanics sent reporters and FIA scrutineers into a spin during the session, when they were spotted spraying a tire with a can of unidentified liquid.

"I have never seen that before in formula one," former driver and BBC commentator Anthony Davidson said.

It turned out the can contained only water, as the mechanics were hunting for an apparent small puncture.

It has been confirmed that BMW's Nick Heidfeld, but hot his taller teammate Robert Kubica, will again use KERS this weekend.

It was a hot and humid practice session, with heavy cloud overhead and a few minor spots of rain.

Heikki Kovalainen dealt with the heat by clutching at a bag of ice when in the garage, while Red Bull's Sebastian Vettel revealed on Friday that he is using a bag of dry-ice this weekend "which I put next to my balls".

Practice 3 Results