Gene drove 25 laps of the Bahrain track in a Williams

Williams' test driver Marc Gene is the only man to drive a Formula One car on the new track in the desert.

But technical director Patrick Head said: "We did just 25 laps, which will probably help us for the first half an hour of the first session in Bahrain.

"But the other teams will soon catch up once they start running."

Spaniard Gene drove one of Williams' 2003 cars at the circuit's official opening last week.

Head said Williams had been surprised by the grip levels on the track, which teams worry might suffer from having sand blown on to the surface.

Williams have a small advantage there Ron Dennis McLaren boss Bahrain F1 track praised

"Even though there was a lot of grit blowing around, grip levels on the track were not too bad," he told the Guardian.

"It should be fine as long as there is not a sand storm, in which case conditions could be very difficult."

Track temperatures in excess of 40C are expected at the race on 4 April, which may give Williams another chance of beating the dominant Ferrari team.

Williams driver Juan Pablo Montoya chased winner Michael Schumacher all the way in Malaysia on Sunday but had to settle for second place.

McLaren boss Ron Dennis told a news conference at Sunday's Malaysian Grand Prix he felt Williams, who use the same Michelin tyres as his team, had gained some useful data.

"We like to survey the circuits with GPS (Global Positioning Systems) and I think that gives you the ability to very accurately put those parameters into your simulation tools," he said.

"So I think Williams have a small advantage there and we were a bit disappointed to be denied the opportunity to actually go and do that."