Nico Hulkenberg expects Sauber to be in the competitive mix this season after describing the laptimes as being "like qualifying" at times during testing.
The Sauber newcomer was fifth fastest yesterday and was agreed that the new C32 is a "fast car".
"At one point I was looking at the timing monitor and it looked like qualifying, it [the laptimes] were separated by only a few hundredths so we should happy with the two days," said Hulkenberg.
"The car performed reasonably well. It's something we can build on, so I think it's a good baseline.
"It needs further development. We know in Formula 1 you cannot stop."
Hulkenberg added that after two days of driving, he is now more comfortable in the Sauber.
He insists that he is not having major problems with accommodation in the cockpit despite being significantly taller than his predecessors at Sauber.
"I've got a bit more comfortable with the car," he said. "The first two days in the office, obviously quite a few things and items to get used to.
"My main priority was to come here to make sure I'm comfortable in the car,seating-wise, comfort-wise and obviously with the steering wheel.
"We've made some little tweaks and modifications so we're going the right way."
Team-mate Esteban Gutierrez has taken over the Sauber for the final two days of the Jerez test.