Nico Hulkenberg 'convinced' he had a problem in F1 Italian GP

The German could not keep pace with team-mate Sergio Perez in the Monza race, finishing 19 seconds behind in seventh place and under heavy pressure from Marcus Ericsson's Sauber and Daniel Ricciardo's Red Bull late on.

"I'm quite frustrated to be honest, because I didn't have the pace all race long and I'm convinced that there's something wrong with the car," Hulkenberg said.

"From Friday to Saturday we changed something on the car and the car was never the same since.

"In the race there was no chance to follow Checo.

"It just wasn't in the car. It was just sliding, eating up the rear tyres.

"On Friday it looked very promising, but on Saturday there was a problem in Q3 and in the race I was fighting I was fighting with a weapon that wasn't really a weapon."

He admitted he had considered switching to a two-stop strategy in desperation as the Force India degraded its tyres.

"There was talk [of a second stop] because I wasn't happy at all and didn't think I would make it to the end defending from Ericsson because it felt pretty bad at one point through the second stint," Hulkenberg said.

Hulkenberg denied that Pirelli's higher tyre pressure guidelines for the Italian GP would have been a factor in his problems.

"No absolutely not, I think it's related to our car and what we've done overnight from Friday to Saturday - purely that," he said.

"We must investigate that and get to the bottom of it, because [performance] was quite significantly down."