Sauber has eye on 2016 F1 car with update for Singapore Grand Prix

Sauber scored a double-points finish in the season-opener in Australia - with Felipe Nasr an impressive fifth - and again in China, since when the Swiss team has predominantly struggled as few updates have been added to the C34.

With the car now boasting an improved power unit since the summer break from supplier Ferrari, the next step for Sauber is a significant development in the chassis - which includes a new nose and front wing - in Singapore.

"The chassis update is not looking that bad," Kaltenborn told AUTOSPORT.

"What we put on that will be important and effective for the following year's car.

"We have very much kept 2016 in mind and tried to change many concepts in how we think about the car.

"Sauber cars have always had weaknesses. Yes, for one or two years we didn't have them, but now we're back to them.

"It takes some time to get out of that, but I think we have reached a point where conceptually we have brought up something else, and I think that will show in next year's car."

After sitting as high as fifth in the constructors' championship early in the season, Sauber has dropped to eighth as other teams have out-developed the outfit.

However, Kaltenborn said the team was prepared for that to happen, and highlighted the improved performance compared to last year when the team failed to score a point.

"Before the season started, we were at a point where it couldn't get any worse so it was not difficult to define where we wanted to go to," added Kaltenborn.

"We knew we had to catch up a lot and that the whole package had to get more competitive, which it did prove to be.

"We also knew it would not be easy to keep up this season after the first few races, that's why we have to set our focus points at different parts in the season.

"If you're limited on the development side, you cannot bring something to every race.

"So we focused more on the the beginning of the season and we knew the next development would be later in the season.

"We knew at that point it would probably be the second-half of the season - and we stuck to that."