Jenson Button of McLaren was fastest as Formula One's penultimate test session ended without rain.
The defending champion's lap of 1 minute, 18.871 seconds set the pace as the 11 cars ran in dry conditions for only the second of eight testing days at the Jerez Circuit.
Renault's Robert Kubica was more than two-tenths of a second behind for second place, followed by Kamui Kobayashi of Sauber, Tonio Liuzzi of Force India and Nico Rosberg of Mercedes GP rounding out the top five. Rosberg was within 1.190 seconds of Button.
Fernando Alonso of Ferrari was sixth with a best time of 1:20.436 as most teams concentrated on long fuel runs. Jarno Trulli made his Lotus debut with a best time of 1:23.470 from a session-high 141 laps.