The BMW WilliamsF1 Team moved to the Jerez circuit to commence another test session in the lead up to Christmas. At the track was Ralf Schumacher and test driver Marc Gené, with both drivers aiming to continue development work on the new BMW V10 P83 engine, tyres, and system setups.

The team would be presented with a wet track after the circuit was hit by heavy showers overnight. As the day progressed the weather would improve with the temperature reaching 22 degrees Celsius.

With the wet conditions the team took the opportunity to conduct tyre testing for Michelin. This tyre testing would see Ralf focusing on various tyre constructions while Marc would test various compounds. As the conditions improved in the afternoon both drivers were able to start systems and engine testing.

For Ralf his day would see him finish with the third fastest time, with a best lap of 1m:21.872. Ralf focused on testing aerodynamic components and he joined Marc in testing the teams the traction control system. The young Renault driver Fernando Alonso was fastest at 1:21.782 minutes. On Friday, the BMW WilliamsF1 Team is continuing its test drives.

For Marc he would again be allowed to use the new P83 engine. He would also conduct tests covering brakes and traction control. After sixty laps Marc would set a best time of 1m:23.811.

At the end of the day WilliamsF1 Test Team Manager Tim Newton commented on the days testing by saying: "We had a wet start to the day after all night rainfall, we took advantage of the dampened track to do some wet tyre work with Michelin. This then progressed to slick tyres as the track begun to dry out by 11.30.

The rest of the day consisted of warm and sunny conditions. Ralf was focusing on systems and brake work completing 81 laps. Marc continued progress with the new engine in addition to system and brake work. Tomorrow we are expecting a similar weather forecast so we can start dry tyre work."

As for the other teams present it would be Renault F1 driver Fernando Alonso who would set the fastest time, with a best lap of 1m:21.782, ahead of McLaren test driver Alex Wurz. For Renault their test would see them evaluate a completely new suspension system.

The only events of the day were when red flags had to be shown when Wurz stalled his McLaren and again when Jaguar's Mark Webber had another failure with the new engine from Cosworth. Jaguar team-mate Antonio Pizzonia would finish the day in fifth position.

McLaren's Kimi Raikkonen was fourth, Renault's Jarno Trulli sixth. For the WilliamsF1 team testing will continue on Friday and over the weekend.