Heidfeld encouraged by BMW reliability

The new F1.07 has been fast but fragile in winter testing, with hydraulic and gearbox issues causing several interruptions to the team's pre-season running.

It has put a dampener on the impressive speed they have shown, which has left several of the German car manufacturer's rivals convinced that Heidfeld and teammate Robert Kubica are going to fight for victory.

Although team sources suggest that BMW-Sauber are considering revisions to the gearbox and hydraulics concept for the start of the season to avoid any early trouble in the flyaway races, Heidfeld has said that he feels some relief by the amount of running he was able to do at Sakhir today.

"I am pleased, yes, because of the long distance I have done without any problems," he told autosport.com. "All throughout winter testing we had the problem, so I think we are on top of it. It (reliability) was my concern really."

Heidfeld was very fast on the second day of testing in Bahrain as he comfortably outpaced the McLaren of world champion Fernando Alonso by eight tenths of a second.

But the German has played down the relevance of the time after admitting that it had come during a qualifying simulation run.

He thinks it was more important that both he and Kubica were able to complete race distance runs in the heat of Bahrain.

"Of course we have a fast car, but we always want more," he said. "The laptime was, you know, one laptime so I am not concerned about that.

"It is nice but it was important to get the long distance. I think the Ferraris are still quickest so we have to work on our speed really, but it was a very good day."

Heidfeld also said that his experience of the two types of tyre compounds used today was interesting - especially with drivers having to use both the hard and medium rubber in the race.

"In today's condition the difference between the hard and the medium was marginal, but you get more degradation with the less hard ones," he said. "So it could be interesting in the race here. I am sure it will be hotter, so the choice will be difficult."