Nico Rosberg insists that Mercedes can say it has achieved its target for the 2012 F1 season despite failing to build on the promise displayed earlier in the year.

Rosberg secured the first win for the team since it took over Brawn GP when he stormed to victory in China, but the Brackley-based squad has failed to launch a championship challenge on the back of that win.

Indeed, Mercedes is now heading into the final seven races of the season trying to defend fifth in the standings from Sauber but Rosberg insisted that steps were being taken in the right direction.

"Our target for this year was to do better than last year, and I think we can say we managed to achieve that," he told Reuters. "Winning in China and finishing second in Monaco were great results. So it's got to be seen as a positive year. But now we've ticked that box and we have to progress further, so now our challenge is to win several races.

"I think we're on the right path. When you see at the factory now, there's so many new people that have been recruited. Top people, really the best in the sport and they're all starting to work together. So it's only a matter of time before we build the best racing car."

Rosberg added that one thing Merceded did need to improve on was reliability, with team-mate Michael Schumacher having suffered a number of issues over the course of the year.

"His car is the same, he's been a bit more unfortunate," he said, "or maybe I'm the car whisperer!

"The consistency has been good, but we've had a few technical issues we've been working on because if the day comes when we're fighting for the championship we have to make sure that the car is flawless, 100 per cent reliable."