Theissen expects slow start for BMW

"It will be an interesting comparison," said Theissen during the launch of BMW's 2006 challenger in Valencia, Spain.

"Certainly Williams starts from a higher level. Williams has 500 people today, Sauber has 280 plus the people who will join the team during the year, so I expect Williams initially to be stronger than us, and we have to catch up."

BMW supplied engines to Williams from 2000 to 2005, but the partnership went awry and the German carmaker decided to buy the Sauber team and race under its own name.

Although Theissen expects BMW to raise the game as the season progresses, the German has ruled out fighting at the top this year.

"I think it would not be realistic to say we car win a race in 2006," said Theissen. "We certainly hope to get close as possible and for sure we will be ready for when the chance is there.

"But you cannot plan for a race win, you can plan for the performance ramp up of the car and then look at what competition does, and then be there when the chance is there. So no predictions, sorry."

Theissen also backed the team's launch date, saying it has given them enough time to design the car but leaving them with sufficient space to prepare it for the first race of the season.

"It certainly reflects the spirit of F1 that every team tries something different in order to differentiate from the competition," Theissen said, referring to Toyota's decision to unveil their car in December.

"A few years ago some teams were late with their car and said this was the right approach, but that was proved wrong, and now we have one team which came up with a car that came up very early, I am not sure that always the rationale given for this is really the truth.

"My impression is that we have a break of four months in the winter time and you best take these four months to develop the car and get it ready for racing, I think the standard way of coming out with a new car in January and then have at least four or five weeks of testing before the season starts is still the right approach."