Mercedes results too up and down says Ross Brawn

Mercedes must achieve more consistent results, boss Ross Brawn has demanded ahead of the German Grand Prix.

He is unhappy at their inability to finish higher up the field in 2012, despite having a more competitive car than in the two previous seasons.

"Our performance has been up and down recently, ranging from podiums to lower points finishes," said Brawn.

"We need to work hard to improve our level of consistency and ability to challenge at the front."

Last time out Mercedes finished seventh with Michael Schumacher and 15th with Nico Rosberg in the British Grand Prix, helping confirm former Ferrari team principal Brawn's concerns about consistency - Schumacher had finished on the podium in third two weeks' previously in Valencia.

This season Brackley-based Mercedes have, at times, been able to keep pace with front runners Ferrari, McLaren and Red Bull, and they were dominant in China as Nico Rosberg secured his first career victory.

But their F1 W03 car appears to be more sensitive than its competitors to the differences found among the circuits in the Formula 1 calendar.

"The Hockenheim layout [the venue for the German Grand Prix on 22 July] should be more suited to the F1 W03 than the high-speed Silverstone layout," Brawn added.

"We are bringing some further improvements to the car which should help our performance."

Mercedes, whose factory is based near Hockenheim, will want to put on a good show for the German public, especially the talismanic Schumacher, who has born the brunt of the team's reliability problems this season.

"As a German driver, you know that all the spectators in the grandstands are supporting you. That makes you proud, and always boosts your motivation even higher," said the seven-time world champion.

"This year is the first time that our Mercedes works team has been capable of racing right at the front and, because of that, we're hoping for lots of support from the fans and to reward them with our performance."

Schumacher's team-mate Rosberg echoed Brawn's view that the Hockenheim circuit will favour the Mercedes car, giving the team a better chance of success.

"I think our car should suit this track much better than Silverstone. Hockenheim has long straights and short corners, which will be good for the Silver Arrow," said Rosberg.

Meanwhile, Lotus driver Romain Grosjean has been handed a five-place grid penalty after gearbox problems in the last lap at Silverstone forced the team to change it for the German Grand Prix.