Simon Trummer went quickest in Thursday's GP3 test at Valencia, ahead of this weekend's round in support of the European Grand Prix.
The Jenzer Motorsport driver set his best time early in the morning when the track conditions were at their peak and most teams elected to get their new tire runs in. Robert Wickens was second fastest in the morning and went on to top the times in the slower afternoon segment.
Dean Smith was third for Carlin, setting his best time in the afternoon after being halted by fuel pressure problems earlier in the day.
Jean-Eric Vergne, Esteban Gutierrez, Nigel Melker and James Jakes completed the top six in the morning, with Gutierrez, Michael Christensen and Renger van der Zande doing the same in the afternoon.
Christensen and Lucas Foresti caused red flags with spins during the day's running, and GP3 rookie Emmanuel Piget and Jean-Eric Vergne stopped their cars on track with mechanical problems.