Rosberg says car was just not fast enough

The German, whose chances of a good result were already compromised by a grid penalty, was unable to climb up the field in the race.

"In Canada, I was fighting the Ferraris and the BMWs, and here I was fighting at the back of the pack," said Rosberg. "It's incredible, and not a very nice feeling.

"I thought I would be able to fight a bit more; I was giving it my all as usual, but the car simply didn't have the speed and it was very difficult. I am now looking to score some points at Silverstone - at least I won't have a grid penalty there."

Rosberg finished right behind teammate Kazuki Nakajima, who completed a dismal weekend for the Williams team.

"It was a difficult race for us," Nakajima said. "We decided to go for a two-stop strategy, which was the best direction to take under the circumstances. All weekend we've been suffering with a lack of pace and that hurt us during the race.

"We couldn't have done much better today."