Rubens Barrichello, Williams, Jerez testingRubens Barrichello put Williams on top of the times at the Jerez circuit on Thursday, as poor weather conditions continued to hamper the teams' preparations for the start of the season.

The session started on a damp track and, despite spells without rain, the asphalt was never completely dry during the day. Barrichello set his best time around midday, when the conditions were at its best, and stayed there as rain made its return moments later. The rain came and went throughout the rest of the day, making sure that the track conditions were far from ideal until the checkered flag was waved.

Renault's Vitaly Petrov also made the most of the conditions around 1 p.m. to post the second-quickest time, ahead of yesterday's pacesetter Sebastian Vettel, who completed 70 laps with the Red Bull. Nico Rosberg was fourth quickest for Mercedes GP, with Felipe Massa rounding up the top five in the Ferrari.

Virgin Racing had a much more productive day than yesterday, when Timo Glock managed just 10 laps. Today the German driver completed 72 on his way to the eighth-fastest time of the day. Glock's session, however, was not trouble-free, as he caused two red flags when he went off the track.

The Lotus team, who enjoyed a very promising day on its T127's initial run yesterday, was not so lucky today when Heikki Kovalainen took over from third driver Fairuz Fauzy. The Finn lost control of his car around 1 p.m. and made contact with the tire barriers, damaging the front wing.

With Lotus not having a spare part on track, the team was forced to miss the remaining part of the session, having completed just 30 laps. Kovalainen admitted afterward that he had simply made a mistake and was sorry for the valuable time lost. Pedro de la Rosa and his Sauber team were worse off, however, as the Spaniard completed just eight laps in the morning and never returned to the track, the team deciding it was not worth running.

"With the same mixed conditions as yesterday, it simply wasn't worth doing much driving today," de la Rosa said. "We have a good understanding of the car, and I'm looking forward to the next test in Barcelona, hopefully on a dry track."

There were a total of four red flags during the session: two caused by Glock, one by Kovalainen and another one by Barrichello.

Today's times:

Pos  Driver        Team                      Time     Laps
 1.  Barrichello   Williams-Cosworth    (B)  1:27.145   70
 2.  Petrov        Renault              (B)  1:27.828   57
 3.  Vettel        Red Bull-Renault     (B)  1:28.162   92
 4.  Rosberg       Mercedes GP          (B)  1:28.515   57
 5.  Massa         Ferrari              (B)  1:28.879    8
 6.  de la Rosa    BMW-Sauber           (B)  1:29.691   33
 7.  di Resta      Force India-Mercedes (B)  1:30.344   56
 8.  Glock         Virgin-Cosworth      (B)  1:30.476   98
 9.  Liuzzi        Force India-Mercedes (B)  1:30.666   71
10.  Hamilton      McLaren-Mercedes     (B)  1:31.633   72
11.  Buemi         Toro Rosso-Ferrari   (B)  1:32.678   24
12.  Kovalainen    Lotus-Cosworth       (B)  1:33.554   30

All Timing Unofficial