Rosberg tops wet first day at Jerez

The 24-year-old was fastest during the first hour before the rain, setting a best time of 1m20.927s to shade Scuderia Toro Rosso's Sebastien Buemi by just 0.104s.

Despite topping the times, his day ended badly as he brought out the red flag with 10 minutes remaining after stopping on track on his 58th lap.

But Rosberg was still content at the end of the session, having felt much more comfortable in the car than he had at Valencia last week.

"The car felt very good today," he said. "Compared to Valencia where I was sitting too low which affected my visibility and the set-up wasn't perfect, today I felt really comfortable and I could push so it was an enjoyable day and a good start to the test for me."

Because of the bad weather, drivers' fastest lap times were all set in the first hour, with the new Red Bull RB6 ending near the foot of the times because Mark Webber's lap was posted while the car was still going through the installation process.

The Australian completed 47 laps before being forced to stop on track with an oil leak, and was only able to rejoin the session in the final 15 minutes as the problem meant an engine change was required. However, the late red flag meant that he could only manage another three laps.

"It's frustrating that a problem with a simple component late morning forced an engine change later in the day, as it cost us quite a lot of time," said the team's head of race engineering Ian Morgan.

"However, the most disappointing thing today was the weather - it's good to have a test in the wet, but it's not ideal when it's your first. We're hoping for better conditions tomorrow when we will continue working through the new car system checks."

The Force India VJM03 also ran in public for the first time, with Vitantonio Liuzzi driving the car that Adrian Sutil shook down at Silverstone.

The Italian was seventh fastest, four seconds off Rosberg's mark, but like Webber the time was set while the car was completing installation laps after missing last week's Valencia test.

"In the dry, the balance felt good," said Liuzzi, who completed 71 laps. "Although when it started to rain it made it more difficult to judge how the car was."

Williams racked up more miles on the Cosworth engine on only the powerplant's second full test since 2006. Nico Hulkenberg, who set the third fastest time when the track was in good shape in the first hour, completed 118 laps and the team reported that it was happy with progress.

Hulkenberg was also one of the fastest drivers in the wet, setting a 1m25.950s in the penultimate hour before the rain got worse.

Fernando Alonso, on his second appearance in the Ferrari, was fourth fastest. The Spaniard missed most of the morning running after setting his time early on, but the team's hopes that the track would dry were unfulilled and he completed several longer runs in the afternoon, racking up 88 laps.

"We're satisfied, because we could collect lots of data, which is important for the reliability," Alonso said. "We hope that the weather is better tomorrow, because it's important to drive on a dry track, too.

"The car went very well on the wet track though and it's easy to drive. The feeling is good, just like on the dry. All in all I had some positive sensations today."

Sauber's Kamui Kobayashi also had a restricted programme because of the weather, running regularly throughout the day but completing only 55 laps. The Japanese was fifth fastest overall ahead of Jenson Button, whose McLaren was fitted with some attention-grabbing aero sensor equipment as the team attempted to maximise the data gathered.

Vitaly Petrov completed only 27 laps on his second day in the Renault R30. After setting his fastest time in the first hour, he stayed in the pits until the afternoon, but despite having no mechanical problems the team preferred to limit his track time.

"I usually enjoy driving in the wet but it was annoying to lose so my much track time to the weather," Petrov said. "Hopefully we will have better conditions later in the week."

The new Virgin VR-01 made its first public appearance in the hands of German Timo Glock. The team flew out new parts that arrived in Spain on Tuesday night and weren't able to hit the track until the afternoon.

After two installation laps, Glock completed a three-lap run in mid-afternoon, setting a best time of 1m38.734s.

Testing continues tomorrow, with the only scheduled driver change being Michael Schumacher stepping in at Mercedes in place of Rosberg.

Pos Driver              Team           Time           Gap   Laps
 1. Nico Rosberg        Mercedes       1m20.927s              57
 2. Sebastien Buemi     Toro Rosso     1m21.031s   +0.104     84
 3. Nico Hulkenberg     Williams       1m22.243s   +1.316    118
 4. Fernando Alonso     Ferrari        1m22.895s   +1.968     88
 5. Kamui Kobayashi     Sauber         1m23.287s   +2.860     55
 6. Jenson Button       McLaren        1m24.947s   +4.020     68
 7. Vitantonio Liuzzi   Force India    1m24.968s   +4.041     71
 8. Vitaly Petrov       Renault        1m25.440s   +4.513     27
 9. Mark Webber         Red Bull       1m26.502s   +5.575     50
10. Timo Glock          Virgin         1m38.734s  +17.807      5