Renault admits its 2011 car and exhaust concept was a 'bold failure'

The system looked like it might have been a masterstroke when Renault produced strong times early in winter testing, but it never delivered the performance gains expected and ultimately limited the team's development ability this year.

"I regard it as a bold, but ultimately failed experiment," said Allison. "We were the only team to adopt a forward exhaust layout, and we did so with high hopes, buoyed by very strong windtunnel numbers."

He admitted that even in the promising early tests Renault had actually been disappointed with the car.

"We came out of the blocks adequately well, although it was clear from the first test that the delivered downforce was not as high as we had expected," he said.

"The season which followed has been difficult for everyone at Enstone. The layout which had promised so much, and which, had it delivered, would have been almost impossible to copy, proved very tricky to develop and had a fundamental weakness in slow corners that has been an albatross around our neck all year.

"We look forward to moving on in 2012 with all-new exhaust rules and a chance to wipe the slate clean."

Team boss Eric Boullier said it had been hard to keep the squad buoyant what subsequently turned into a frustrating year, but felt morale had not wavered too badly.

"When you score points and achieve positive results, it helps a team's motivation and keeps people upbeat," said Boullier.

"Contrarily, when a team is suffering from lack of form and other adversity it becomes challenging to keep the spirits of the troops high.

"During a long, hard season that challenge becomes more prevalent, and hopefully we have managed to keep morale at a reasonable level during the hard times we have faced in recent weeks. India and Abu Dhabi were poor races from our perspective, but it's important that we maintain our focus and enjoy the last race of the season."