BMW-Sauber is preparing to introduce a 'multi-level diffuser' for next weekend's Turkish Grand Prix in Istanbul in a bid to help the team overcome what Mario Theissen has described as the Bavarian outfit's 'first setback' since its arrival in Formula 1 as a manufacturer in its own right three years ago.

An abject performance in the Monaco Grand Prix last weekend - with Nick Heidfeld and Robert Kubica qualifying respectively just 17th and 18th and the former going on to take the chequered flag a lowly and lapped eleventh as the latter retired with brake issues less than halfway through - was inarguably one of BMW's worst showings in 59 races.

With a mere half dozen points on the board from the opening six outings of the 2009 campaign, the Munich and Hinwil-based concern currently sits just eighth in the constructors' title chase, behind every one of its chief rivals Ferrari, McLaren-Mercedes and Renault. BMW Motorsport Director Theissen is adamant that the situation cannot be permitted to endure.

"After three years, in which we have always achieved and even surpassed our goals, this is the first setback," the German stated. "We have to put this behind us - and we will do. After all, the very same team in Munich and Hinwil is responsible for the BMW-Sauber F1 team's consistent improvement since its formation. The same team gave us our first pole position and put us on the very top of the podium. As a result, everyone is ready and motivated for the fight ahead, as we strive to return to the top.

"A better result was not possible for us [in Monaco]. At no point was our car competitive, and no points are the result. Robert had a damaged tyre on lap two and later on suffered from brake problems, which caused him to retire. Nick was the first driver to change to the softer tyre compound after a long first stint. Nobody else was on 'Option' tyres for such a long period, and they degraded dramatically before recovering a little towards the end of the race.

"We have to improve our speed of development significantly in order to match our own expectations. At the next race in Istanbul we will line up with another new development package. We will use a multi-level diffuser for the first time in Turkey, and we are convinced that this will be another step in the right direction."

"After the free practice and qualifying sessions it was clear that the race would be difficult," added head of engineering Willy Rampf. "Nick's race ran without any special incidents. In the closing laps he was able to defend his position against Lewis [Hamilton] with worn-out soft tyres.

"Robert had a flat tyre early in the race. Surprisingly, he was then able to do good lap times with a very heavy car. We had to bring his car back to the pits early due to a brake problem. Overall, this was a disappointing weekend. It is now our goal to be competitive again in Istanbul. A lot of work lies ahead of us."

The drivers were similarly depressed about the outcome of the race around the tortuous, unforgiving streets of the glamorous Principality, where both have in the past been rostrum finishers. All at BMW, you sense, are steeling themselves for the long road back.

"I tried to make up positions at the start and on the first lap," recounted Heidfeld, "but this time it just didn't work out. It is too narrow [in Monaco]. I was stuck behind Adrian [Sutil] for quite a while. Apparently he had problems with his tyres, and once I even touched the rear of his car. In turn one Lewis hit me, but I was happy I was able to continue. I was on a one-stop strategy, and with the softer compound in the second stint I had degradation. We gave it everything, but we were too slow."

"We had difficulties over the entire weekend," concurred Kubica. "I had a problem at the start and fell to the back of the grid. Then I had a puncture on my rear right tyre. After the necessary pit-stop I was lapping well with a very heavy car, taking the car's potential into account. In the end I had to retire as I had brake problems."