Barcelona F1 test: Felipe Nasr says Sauber had "too many problems"

Nasr completed just three laps before lunchtime after revealing the team needed to "take the car apart" to fix what the Brazilian described as multiple mechanical issues.

The GP2 graduate said the team managed to salvage its programme in the afternoon, during which he logged 70 laps and set the fourth-best time using super-soft tyres, but he is wary that reduced mileage will hurt its quest to return to scoring points in 2015.

"We had to give up the morning to fix the little problems," he said. "It was too many in general, all on the mechanical side.

"It was best to really do a big review of the car, take the car apart and make sure it was done correctly.

"Of course the more we run, the more problems we can see and solve.

"The problems only come when you have a lot of running of the car and go through different programmes."

The former Williams reserve driver said he is convinced the team had made a step forward from the C33 it failed to score a point with last year, but that it is too early to tell how much progress has been made.

"We don't know to be honest," he said when asked by AUTOSPORT if the team had got any closer to working out if it had closed on its rivals in this test.

"It's difficult to say because you need to have other teams as a reference.

"I can say there is a step forward from last year; there is a step forward from Jerez to here. It's steady progress.

"They are totally focused on the points. We all want to get back to points.

"I would say it's not only one area, it's many areas that has to be improved. I think there is some already compared to last year."