Nick Heidfeld says he is still concerned about the dubious reliability of BMW Sauber's 2007 car.
The German is being touted as a dark horse for next weekend's season opener in Australia, but to the news agency 'sid' he admitted that the Hinwil built racer is still too fragile
"We have worries about the hydraulics and the transmission, even still" Heidfeld, 29, said.
It was reported that, at the recent Bahrain test, Heidfeld's team successfully completed a full race simulation with two of the new cars.
He insists: "We are not completely relaxed about the first race, but I have said before that I would rather have a fast car that is not perfectly reliable than the other way around.
"We would however be happier if we had fewer problems."
The Stig