Nico Rosberg edged out team-mate Lewis Hamilton in a close opening practice session ahead of the Spanish Grand Prix.
The two Mercedes drivers were comfortably clear of Ferrari at the top of the times but traded fastest laps throughout the session before Rosberg came out on top with a 1:26.828. Despite the fastest time - 0.07s quicker than Hamilton - Rosberg is under investigation after making a late decision to pit and cutting across in to the pit lane beyond a bollard at the entry.
The two Ferraris were third and fourth - Sebastian Vettel just ahead of team-mate Kimi Raikkonen - but were a second adrift of the early pace set by Mercedes. Raikkonen was also complaining of issues with the front end of his car throughout the session, before later saying his seat was getting too hot in the cockpit.
Toro Rosso enjoyed a strong start to the weekend as Carlos Sainz and Max Verstappen finished the opening session fifth and sixth respectively. However, things did not go so smoothly at Red Bull as Daniel Ricciardo suffered more Renault-based woes. Ricciardo said on Thursday he would be limiting running to protect his power unit - already on the fourth of four available this season - but spent most of the session in the pits and only managed 9 laps.
Ricciardo's late running did allow him to move up to ninth place, and actually took him above team-mate Daniil Kvyat in terms of laps completed. Kvyat finished the session seventh and was running a new front wing for Red Bull, with the team bringing a shorter nose to Barcelona.
Sandwiched between the two Red Bulls was Felipe Massa's Williams, with Felipe Nasr rounding out the top ten. The second Sauber was driven by reserve driver Raffaele Marciello, who did a solid job to end the session in 12th place despite a big moment when he ran wide at Turn 9.
Jolyon Palmer (Lotus) and Susie Wolff (Williams) were also taking part in FP1, finishing directly behind Marciello and ahead of the two McLarens of Fernando Alonso and Jenson Button. Alonso had a spin at Turn 12 right at the end of the session having been struggling with the handling of the updated MP4-30, while Button complained that the balance was "completely wrong".
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| Pos | Driver | Team | Time | Laps |
|---|---|---|---|---|
| 01 | Nico Rosberg | Mercedes | 1:26.828 | 28 |
| 02 | Lewis Hamilton | Mercedes | 1:26.898 | 27 |
| 03 | Sebastian Vettel | Ferrari | 1:27.806 | 21 |
| 04 | Kimi Raikkonen | Ferrari | 1:27.832 | 16 |
| 05 | Carlos Sainz | Toro Rosso | 1:28.132 | 27 |
| 06 | Max Verstappen | Toro Rosso | 1:28.529 | 23 |
| 07 | Daniil Kvyat | Red Bull | 1:28.785 | 7 |
| 08 | Felipe Massa | Williams | 1:28.831 | 21 |
| 09 | Daniel Ricciardo | Red Bull | 1:29.075 | 9 |
| 10 | Felipe Nasr | Sauber | 1:29.140 | 14 |
| 11 | Nico Hulkenberg | Force India | 1:29.409 | 20 |
| 12 | Raffaele Marciello | Sauber | 1:29.630 | 15 |
| 13 | Jolyon Palmer | Lotus | 1:29.676 | 21 |
| 14 | Susie Wolff | Williams | 1:29.708 | 22 |
| 15 | Fernando Alonso | McLaren | 1:29.813 | 22 |
| 16 | Jenson Button | McLaren | 1:29.817 | 22 |
| 17 | Sergio Perez | Force India | 1:30.096 | 19 |
| 18 | Pastor Maldonado | Lotus | 1:30.110 | 7 |
| 19 | Will Stevens | Manor | 1:32.471 | 22 |
| 20 | Roberto Merhi | Manor | 1:32.647 | 20 |
