Red Bull duo frustrated by poor race

Klien, who will leave the team at the end of the season, had started from a promising 10th position, but the Austrian endured a tough race and finished down in 11th.

"That was one of the toughest races this season," said Klien. "It was so hot and Turn eight is such a long corner, it's very tough on the neck, but I kept pushing until the end. The car was good in the first stint and had good balance, but I suffered with understeer in the second part.

"In the last section, the car was a little better again, but we were not really racing here today. It's frustrating to start tenth and finish eleventh."

The day was worse for Coulthard, who retired from the race with three laps remaining while running ahead of his teammate.

"Not the result we wanted today," said the Scot. "The balance of the car was okay and improved after we adjusted the front wing and tyre pressures during the first pit stop. We were competitive in sections of the race compared to the cars around us and towards the end of the race I was catching Webber.

"I thought I could overtake him, but I had to retire with a gearbox problem."