"A tricky session here in Bahrain today," admitted McLaren team principal Martin Whitmarsh at the end of Friday's practice sessions. But he didn't mean that in an altogether bad way, and felt that progress had been made getting to grips with the desert conditions despite less than ideal relative lap times for his drivers.

"While the lap times don't reflect it, our long-run pace looks reasonably promising," he insisted. "I'm confident that we'll establish a good baseline for tomorrow's running."

"My times haven't looked great all day," admitted Jenson Button. "Over a single lap, the Mercedes and the Red Bull both look quick. There's a big margin to the front at the moment - but I don't think it will be the same in the race."

Finding decent balance and grip on the hot, dusty track was top of the list of priorities for both drivers. Added to that was a strong wind blowing across the Bahrain International Circuit at Sakhir.

"Neither Jenson nor Lewis felt completely satisfied with the car's balance," agreed Whitmarsh. "We spent the afternoon pursuing a number of set-up options in order to establish a clearer direction for the remainder of the weekend," he continued, praising the "excellent feedback" from both drivers during the day.

"I just don't feel completely happy with the direction we've chosen," said Button bluntly. "The car's been acting very differently from how it's been in the first three races. Perhaps we've gone too far with the balance and need to take a step back."

"Overall, a tough day; a tough challenge," stated Lewis Hamilton. "Looking after the tyres here is going to be a real challenge. The track surface is extremely hot, and the amount of energy that goes through the tyres under braking is incredible: the temperatures keep on rising until it feels just like driving on an ice-rink ... Tyre degradation will be a big issue for everyone around here and the weekend will be all about who can look after the tyres the best," he suggested.

The wind was also a big factor for Hamilton during the day.

"On one lap, there'd be a headwind going into turn 4, the next lap, it'd be a tailwind, then a crosswind," he recalled. "That makes a big difference around the circuit. I think my fastest lap was set half an hour after Nico set the fastest time of the session, and the wind was very different."

However, both drivers were optimistic that the situation would be better for Saturday and the race on Sunday.

"I'm hopeful of resolving the issues before tomorrow," said Button. "We've started talking about what we can do for tomorrow and there are already some positive comments about which direction to take."

"We're there or thereabouts," insisted Hamilton. "But we'll know more tomorrow."