Monday 16 June at 14:33 : Team founder Peter Sauber doubts that BMW-Sauber is ready to challenge for the 2008 titles.

While heralding the Hinwil based team's breakthrough win at Montreal just over a week ago, the Swiss urges caution on expecting too much more too soon.

"The fact is that Ferrari and McLaren are still a little faster than we are," he wrote in a column for the Swiss newspaper Blick.

"And those teams are not going to want to be making as many mistakes as they have until now," Sauber added.

Robert Kubica took the lead in the drivers' standings by four points in Canada, while teammate Nick Heidfeld's second place closed BMW-Sauber to within three points of Ferrari's constructors' championship lead.

Sauber said: "Of course this is a boost to our motivation, but we need to just keep looking to the next race. At the end of the season we will see where we are."

The Hinwil based team's technical director Willy Rampf, however, admits that winning the championship cannot be ruled out.

"Of course you think about it," he is quoted as saying by the Credit Suisse emagazine.

"When you come out of the seventh race of the season with a result like ours, then you begin to get such ideas. But you've got to be realistic too," Rampf said.