Buemi ready to lead Toro Rosso

The Swiss is now Toro Rosso's more experienced driver after Sebastien Bourdais was dropped in favour of reigning British Formula 3 champion Jaime Alguersuari.

He faces a major challenge this weekend with the Faenza-based team running a comprehensive car upgrade, effectively taking the STR4 to equivalent specification to that the Red Bull RB5 ran at last month's British Grand Prix, for the first time.

"Bourdais is now gone, so it will be different," Buemi told AUTOSPORT. "Before, I was the rookie and now I must lead the team.

"I've always tried to do my best, even when Bourdais was there I listened to all of his comments and tried to make things better. But in the end I was also trying to go my own way because this is important.

"I'm confident that we can do a good job."

Buemi hopes that the upgrades, which will make Toro Rosso the last team to run with a double diffuser, will allow him to fight for Q3. Team sources suggest that the developments could be worth as much as one second, depending on the type of track.

"It is a big step, the biggest of the season for us," said Buemi. "To say exactly where it will put us is difficult, but we hope to be back to the level we were in China, where we made Q3 and scored a point.

"We know more or less what that package should bring, but if the others are going to be three-tenths faster, then the amount that we are going faster will not be as much."

Buemi added that it might take a few races for the team to exploit the full potential of its upgraded car because of the restrictions on testing, but expects the STR4 to be close to its ultimate performance very quickly.

"I don't want to look for excuses - we will be more competitive here although we may not be able to use the maximum potential of the package," said Buemi.

"But in F1 you have so many simulations that you are more or less able to set up the car to its maximum.

"We have changed so many things on the car - maybe we will go out on Friday and have a problem like Sebastian Vettel had here last year. If something like that happened it would be difficult, but one or two more races and we will be able to do it."