Karthikeyan reveals qualifying concerns

The new car was unveiled during the final pre-season test at Barcelona but did not actually run, meaning that the Indian - who returns to Formula 1 for the first time since 2004 - and his team-mate Vitantonio Liuzzi have six hours running time between them on Friday to sort out any new-car niggles with the chassis.

"It is a concern," said Karthikeyan in Melbourne on Thursday. "We need a car that is a good step forward, so it should be a positive step but until you try it you never know. We will see what happens, I can go on and on."

Karthikeyan added that he did not feel rusty after such a long lay-off, adding that he was pleased to have the experienced Liuzzi as a benchmark.

"Things have changed a lot, the old car was not too bad, I have a good team-mate in Tonio so easy to see where I am," he said. "We had some mileage in the old car but the new car we have to see how it goes tomorrow, it will be the first time, we have to see what happens."