Esteban Gutierrez's previous experience with Sauber proved a significant benefit on his first day driving in the Abu Dhabi young driver test.
Having signed as the team's reserve driver back in 2010, Gutierrez has since tested for the team on several occasions and made his competitive debut in Friday practice at India, substituting for the ill Sergio Perez.
Gutierrez said that experience helped him hit the ground running on his first day of testing.
"After being in the car so recently in India, of course, I feel a lot more confident in handling all the system like KERS and DRS," he explained.
"The morning session was very interesting for me because we tested a lot of different things, and I hope I gave my most precise feedback to the engineers.
"I used only hard tyres, but in the afternoon I certainly enjoyed running the medium as well as the soft compound."
Sauber's head of track engineering Giampaolo Dall'Ara, meanwhile, admitted that Gutierrez's familiarity with the team had been a boost to Sauber's test programme.
"Obviously we know Esteban a lot better than we knew Robin [Frijns] before yesterday, and he is also quite familiar with the team and the track. This helps for some procedures and communication," Dall'Ara explained.
"Again he did a good and reliable job for us. We basically ticked off everything from today's job list.
"In the morning and early afternoon the focus was on aero work with a set up change over the lunch break.
"Later in the afternoon we repeated the programme we did yesterday with Robin, giving Esteban a set of medium compound tyres as well as a set of softs.
"In the end he did a high fuel run on medium tyres. For tomorrow we have some brake testing and suspension work on the list."
Gutierrez has been linked with a full-time ride at Sauber for 2013.