Sauber admits Ferrari engine not only cause of poor 2014 F1 season

Sauber finished 10th in the constructors' championship and failed to score a point for the first time in 22 seasons in F1.

While the weakness of the Ferrari power unit was the most significant factor in this, the Swiss squad's team principal accepts that the chassis was also disappointing.

"After the season we had, we have to be very blunt and simple about this; we never expected it would end up like this," Kaltenborn told AUTOSPORT.

"The overall package was just not good enough and we have to learn from this and go ahead.

"There are many factors that have led to this.

"On the chassis side, we have made better cars.

"The car is not as bad as it looks but we have definitely done a better job before and that is where we need to get back again.

"We have the tools for it, we need the funding for it and we are working on that.

"If you make mistakes on top of [the engine] it doesn't end up well."

Kaltenborn has no doubt that Ferrari will improve its engine in 2015 and that, as the rules mature, the competitive spread through the field will tighten.

But while Ferrari's power unit is expected to be closer to Mercedes next year, she accepts that the German manufacturer is still likely to dominate.

"Definitely, the power train has dominated this season and I am very confident that our engine supplier is going to make a step," she said.

"They also cannot do miracles; we still probably will see the dominance of one engine supplier, but I have confidence that the gap will be smaller."