Theissen confident BMW will improve

Robert Kubica and Nick Heidfeld endured a torrid time at the Monaco Grand Prix, with their F1.09 struggling for grip as a lack of downforce compounded problems getting tyre temperatures into their operating range.

But on the back of the disastrous weekend, Theissen remains hopeful that upgrades planned for Turkey, including a double diffuser, plus the return of KERS, will see fortunes lift very quickly.

"We will have an improvement for Turkey and the car should be better suited to that track," explained Theissen. "At the moment it is tough. Of course it is tough.

"This is the first setback after three years of success, and it was unexpected, so it is tough. But then engineers are able to turn this into motivation."

When asked by AUTOSPORT if he felt as confident that BMW Sauber could still fight at the front later in the season as he did after the Spanish Grand Prix, Theissen said: "Yes, absolutely. It is positive thinking. I said before that our people know they can do it, they have done it and they are very eager to get back to where we were."

Theissen is also pretty confident that the weekend's troubles can be put down to tyres - with both his team's cars and the Toyotas struggling with the rubber.

"Yes. Absolutely. We think it was confirmed in the race because what we saw in qualifying and what we saw in the race fits together," he explained.

"We could not get the tyres to work in qualifying. In the race, with more rubber on the track, it worked but then again when the drivers let someone by, and slowed down, immediately it became difficult. The tyres cooled down and the lap times went up."