Whilst times mean very little from Pirelli's tyre test, it was Red Bull's Daniel Ricciardo that was quickest on the opening day as the tyre supplier tested its wet weather tyres at the Paul Ricard Circuit in France.
Only three drivers took part, with Pirelli selecting Red Bull, Ferrari and McLaren for the two-day event.
McLaren's Stoffel Vandoorne was second quickest, but ended the session early due to a technical issue which saw his MP4-30 return to the pits on the back of a recovery vehicle.
Kimi Raikkonen was third for Ferrari, almost a second off the pace.
Overall 285 laps were completed, with Red Bull and Ferrari completing 10 sets of 10-lap runs on Pirelli's new prototype full-wet tyre.
Pirelli Wet Weather Tyre Test – Day 1:
| # | Driver | Team | Time | Gap |
| 1 | Daniel Ricciardo | Red Bull | 1:08.713 | |
| 2 | Stoffel Vandoorne | McLaren | 1:09.131 | +0.418 |
| 3 | Kimi Raikkonen | Ferrari | 1:09.637 | +0.924 |
