Felipe Nasr warns Sauber not to 'throw money' at Formula 1 upgrades

After a strong start to the season, with two double-points finishes in three grands prix, Sauber scored just once in the next six races as rival teams outdeveloped the Swiss outfit.

Nasr said it is important Sauber, which is one of the teams campaigning to bring down F1 costs, spends its limited resources efficiently.

"It is important to stop just throwing money on things that maybe don't work," he said.

"We need to be very targeted, correlating the numbers and making sure they work in the windtunnel.

"On the designer's side, the challenge is to bring something that is going to add a lot for the car.

"I feel the potential of the people who work here is strong. The facilities are there. I feel that things are starting to pick up.

"It's a good move by the team to sign Mark Smith, but we need to have time for these things to work."

Sauber aims to have a Ferrari engine upgrade for the first race after the summer break in Belgium with a chassis update following two races later in Singapore.

The team has brought new parts to the car this season, including a front wing that it introduced early, but it took several races to get the best out of it and Nasr wants to avoid that scenario happening again.

"What we saw with China, with the front wing, that's the kind of thing they don't want to see happening," he said.

"They want to bring something that is a decent step on the car.

"I think, and I'm sure the team has the same mentality, it is better to wait for something that is going to fit properly rather than just throwing things from race to race, seeing if it works.

"It's better to have something concrete that is going to work.

"We need to have a bit of patience as well, to work out what are the key areas to work on."