Daniel Ricciardo has admitted that he was "trying to find the extremities" of his Red Bull car at the first in-season test of 2014 in Bahrain.
The Australian registered the seventh-fastest time on day one of the test, 2.6 seconds slower than pace-setter Nico Rosberg, and despite spending some of the morning in the pit lane due to reliability issues, Ricciardo insists that the session was productive for the constructors' champions.
He told Crash.net: "We missed a little bit of time this morning but we made up for it in the afternoon. I think I sat in the car for a good few hours there at the end and we got through some test items.
"It was more just testing stuff that we don't have time for on a race weekend or we don't have the confidence with some of these changes because we haven't really tested them before.
"It's just trying to find the extremities of the car and the balance. We did some long runs; I think we did three long runs with three set-up changes and got some good feedback from that so pretty good day testing-wise."
Ricciardo recovered from a 10-place grid penalty to finish fourth in Sunday's Bahrain Grand Prix, won by Lewis Hamilton.