For the BMW WilliamsF1 team the opening Friday practice for the 2005 Spanish Grand Prix would only see Nick Heidfeld set a time finishing in third.

Friday practice would see the BAR team suffering a two race ban and would pack to leave the circuit, while Juan Pablo Montoya would make his return after his injury. For the BMW WilliamsF1 team there was the news that the team had found a problem with Nick's engine which would require both Nick and mark to change engines. Nick was suppose to have used this engine for this weekends race so any changed will see him face a penalty of ten grid positions.

With the start of the session it would be Red Bull's Christian Klien first out onto
the track with nine cars joining him, including Montoya. Most drivers would return to their pits after installation laps.

McLaren's Kimi Raikkonen would take to the track, only to return to the pits. Zonta would start his flying lap finishing with a time of 1m:20.816. Klien would return to the track for his first flying lap. Zonta would improve with a 1m:18.794, while Klein would set a time of 1m:22.276. Zonta would again improve his time with a 1m:18.103.

His second lap would see Klein set a time of 1m:19.138. Joining him was two other Friday testers, Pedro de la Rosa and Jordan's Robert Doornbos. Doornbos would set a time of 1m:24.685, while de la Rosa moves into third with a 1m:19.370. de la Rosa would also improve his time with a 1m:18.721.

Michael Schumacher would come out and he was quickly into second with a time of 1m:18.445. The next lap and he would lower his time with a 1m:18.235. The second Ferrari of Rubens Barrichello would take to the circuit, joined by Renault's Giancarlo Fisichella. Both Rubens and Giancarlo would return to their pits after their installation lap.

With over half the session run a lap time of 1m:17.658 would see de la Rosa go
fastest. David Coulthard and Nick Heidfeld were both now out on the track. Montoya's first lap would see him set a time of 1m:18.402. Michael Schumacher would beat de la Rosa's time with a lap of 1m:17.574 to go fastest. But Nick Heidfeld would just as quickly snatch this position from Michael with a time of 1m:17.642. Nick would improve his time with a 1m:17.381.

With fifteen minutes left in the session Pedro de la Rosa would beat Nick's time by a considerable margin with a time of 1m:15.675. Christian Klien would join the quick times, moving into second with a time of 1m:16.821. With less than ten minutes left in the session there was seven drivers that had yet to set a time, including Renault's Fernando Alonso.

Raikkonen would move into fifth with a 1m:17.851. Nick Heidfeld would improve his time to be third with a 1m:17.047. In the final minutes we would have yellow flags for the Minardi of Albers that left the track. Villeneuve would set his best time with a lap of 1m:20.621 to be eleventh, while Ralf Schumacher was now in eighth with a 1m:18.204.