Nico Rosberg was the fastest in the opening day of testing in Barcelona, in wet conditions. Only four teams took part in this test. Williams covered a total of 787 km, developing the car in difficult conditions. Rosberg's teammate Kazuki Nakajima was second, about 1,7 seconds behind the Finn.

Rosberg completed 73 laps making a fastest time of 1:30.675 ans Kazuki Nakajima made 1:32.370 after 96 laps. "The weather really hampered play today in Barcelona. Rosberg and Nakajima were in the cockpit for us and concentrated on set-up work and endurance runs so our running wasn't as adversely affected by the conditions as it perhaps was for others", said Williams test team manager Dickie Stanford.

McLaren and Ferrari are set to join the testing on Wednesday. The timetables after the first day of testing was :

1 N. Rosberg Williams 01:30.675
2 K. Nakajima Williams 01:32.370
3 M. Webber Red Bull 01:32.599
4 F. Alonso Renault 01:32.820
5 D. Coulthard Red Bull 01:32.924
6 J. Trulli Toyota 01:33.283
7 N. Piquet jr. Renault 01:40.073
8 K. Kobayashi Toyota 00:00.000