Colombia's Juan Pablo Montoya has admitted he still does not know how competitive his Williams-BMW will be this season.
Montoya wrote off his championship chances before the season-opening race in Australia 11 days ago then went on to finish second - and but for a costly spin could have won.
But the 27-year-old heads into Sunday's second round in Malaysia admitting he does not know where he will finish.
"It is pretty difficult to say how we will perform in Malaysia. We might be really good or we might be 10th, I don't know," said Montoya, who finished second to team-mate Ralf Schumacher in Kuala Lumpur last year as Williams enjoyed what proved to be their only win of the season.
"The Barcelona circuit is the only fast track we tested on over the winter and we haven't been very quick there. On the other hand we have historically always been really quick in Malaysia.
"I think the hot weather should suit our package and especially our tyres and with the improvements Michelin have made, I am not concerned about the rain."
The unpredictable weather played a major factor in the result in Melbourne and Williams could face a backlash from Michael Schumacher's Ferrari this weekend.
But Montoya insisted he would not be disappointed if Ferrari do return to the victory podium at Sepang and confirm his fears.
"With the basic package we can't take the fight to Ferrari this year," he added. "That's just being honest and realistic.
"If the championship is gone what can we do? We need to try our best at every race. I cannot go and hit Patrick Head (technical director) because the car is not good enough."