Bourdais: team will keep winning

The French driver will leave the team to race for Toro Rosso in F1 next year, and he feels that his team deserve credit for a lot of his success during his five years in America.

"When you look back it's a big achievement (to win four consecutive titles), and it's also, like I said many times, it's a group success," said Bourdais.

"Nobody is really irreplaceable. Obviously a driver is one part of that success, but Carl (Haas) always seems to be able to find the right guy for the job."

The 28-year-old believes that the team's experience of replacing champions in the past proves that they will be able to find a new star.

"It doesn't need to be Sebastien Bourdais," he said. "It's been other people before, and obviously great names, between Michael and Mario (Andretti), Nigel (Mansell), and Cristiano (da Matta).

"I'm sure they'll find someone else that can get it done just as well and build a new group and start a new adventure."