Theissen: BMW on top of car problems

Although he insisted that it would take several races for the developments to correct the aerodynamic problems of the car to come online, he suggested that the major package that the team will bring to September's Singapore Grand Prix will make a big difference.

"We think we have understood [the problems], but it will take some upgrades that cannot come immediately to prove that," said Theissen.

"We will have one step in Valencia and then the final and most important one for Singapore. What we have brought here is a step in between which has been added to the programme."

Development will continue on the F1.09 to the end of the season despite speculation that it would be one of the teams to focus on developing its 2010 car.

However, Theissen underlined that this is a false argument as, aside from the refuelling ban, car concepts will be essentially the same next year.

"The developments feeds in to 2010," he said. "It's a very different situation than what we had last year. Next year's monocoque will be longer, but other than that there is no fundamental difference.

"We will carry on with F1.09 for three reasons. One: the regulations don't change so what we learn can be transferred to next year. Number two: we have the test ban so the only chance to try something out is the race weekend. Number three: we need to understand where we are and how to close the gap to the front, otherwise we cannot be confident about next year's concept."

Theissen is also hopeful that the minor upgrades it has brought to the Hungarian Grand Prix, together with the hot conditions, should help it be more competitive this weekend.

"I hope that we can stronger than before," said Theissen. "We have had severe problems to get the tyres to work in all conditions, but that shouldn't be the case here so that should help us."