BERLIN, Germany - Mercedes is under pressure to succeed after disappointing results through the three years since it rejoined Formula 1 as a works team.Motorsport chief Toto Wolff told DPA: "The pressure for success is great, otherwise it wouldn't be any fun. That's Mercedes-Benz which went into F1 to drive for championships and win championships... that has to be the aim. Perhaps you cannot expect it right away but when a team functions then it generates an amazingly positive image which you can measure in real figures."STILL TO BE SEENThe 41-year-old Austrian has succeeded German Norbert Haug, motorsport chief for 22 years, while Mercedes has acquired Briton Lewis Hamilton, the 2008 World Drivers' champion, from McLaren to team up with German Nico Rosberg on the track.How prepared Mercedes is for the 2013 season, which will open with the Australian GP in Melbourne on Sunday, remains to be seen, Wolff said."The only thing I see are the historical results and what's happened in the few weeks I have been here. I would like to see confirmation in the first races of how the team works, how it functions under pressure, before I can make a judgement."Wolff has, however, been impressed by the impact Hamilton has already had on the team. "A great guy. That once again confirms my own belief that there is a lot more to being a World champion than merely having a strong right foot."He has social intelligence, he is good with people, he knows how to motivate them, he is a meticulous worker. It's a lot of fun to work with professional people. If they are also nice, that's even better. All of us in the team are delighted that Lewis has joined us."'LIKE A MARRIAGE'However Wolff dismissed talk of the first year being a form of apprenticeship at the team for Hamilton after six years in F1 with McLaren. "None of us will be satisfied with a learning year," he said. "We all want the best possible results and are doing everything for this. In the end we are a team, we win or lose together."It's a bit like a marriage. We want to stay together in good and bad times."Wolff forms the management of the Mercedes GP team with fellow Austrian and former World Drivers' champion Niki Lauda and team principal Ross Brawn. The new set-up will not affect Lauda's role as a TV commentator, Wolff said. "You cannot tell someone like Niki Lauda what or what not to do. That would certainly be the wrong signal. He is a three-times World champion."You have to take your hat off to what he has achieved. Niki has great abilities. He is direct and sees things quickly. We want to use these strengths. We have an open relationship and can say everything to each other."'BEST WE CAN'On whether continuing speculation on the future of team principal Brawn had been a distraction, Wolff said: "An F1 team is judged on how quick it is on the track. Everything else is secondary."The car has been developed by (technical director) Bob Bell, (engineering director) Aldo Costa and the technical team. We can give our input as best we can but at the end of the day it plays no role on what is discussed at the owner level."Stay with Wheels24 for the 2013 Formula 1 season – fresh reports every day.