Alonso urges Renault to improve

The two-time world champion spent the first 20 laps of the race stuck behind the more heavily-fuelled BMW Sauber of Nick Heidfeld, costing him time and compromising his two-stop strategy.

He later became involved in a battle with Lewis Hamilton's McLaren, but with the pair fighting only for 14th place at the time, the Spaniard was left demanding changes to his R29.

"It's clear we need to improve on all fronts before Germany," said Alonso. "I'm obviously frustrated with this poor result.

"Our chance to score points today was over at the start as we lost two positions and I was stuck behind Heidfeld, who was heavy on fuel, which cost us a lot of time."

His team-mate Nelson Piquet surprisingly finished two places further up the order, the Brazilian emerging more satisfied with his own performance. He echoed Alonso's sentiments about changes being needed though.

"I think I had a solid race," said Piquet. "I know I have to improve on my qualifying though.

"It's pretty clear that we must continue to work hard and hopefully introduce some new upgrades in time for the next race."