Sauber F1 team surprised by size of Ferrari's engine power gains

Although the team was always supportive of its engine supplier Ferrari and anticipated an improvement this year, Kaltenborn was not expecting such a significant leap forward.

The Ferrari now appears to be the second strongest power unit on the grid behind Mercedes, but a clear step ahead of Renault, after gains reckoned to be worth a second per lap or more over the winter.

"It has been a very big improvement," said Kaltenborn.

"They have really done a good job and I am pleasantly surprised.

"You need that kind of powertrain, it's never just a lone car, it has to be the right package."

Kaltenborn believes that the step made by Ferrari is the most significant factor in Sauber re-emerging as a points-scoring force after a point-less 2014.

With an improved car and engine, as well as a strong performance from Felipe Nasr on his way to fifth in the Australian Grand Prix, she believes Sauber has proved itself ready to seize opportunities for strong results when they arise this season.

"The massive step just allows you to be in a position with the powertrain to score points and then to really grab the opportunity," said Kaltenborn.

"Last year, we couldn't have even had the opportunity because we were that far away.

"That's the big difference to last year; to be, through your own strength, in a much better position, [it means] if opportunities open up you can take them."

She added that while these strong results will not have an instant impact in terms of attracting more commercial partners, the Australian GP was a strong message of intent for Sauber.

"If I look back at 2012, we had really good results there but that didn't mean that on Monday morning I had people standing at the factory trying to sponsor us; it's unfortunately not that easy" said Kaltenborn.

"But it tells people that we are back and let's forget last year, that's just a one-off and it shouldn't happen again.

"What we said is that we want to improve, and we will improve; we have proven that to people and want to put that message out there."