Mercedes led the opening day of the Austrian in-season test thanks to reserve driver Pascal Wehrlein’s 1:11.005.
The German driver finished 0.187 seconds clear of Force India’s Esteban Ocon, who spent the day evaluating new parts which will eventually form the B-spec car which will debut at the British Grand Prix.
The session was almost abandoned due to heavy downpours, with red flafs deployed due to the dangerous conditions.
However things began to improve in the afternoon, leading to some meaningful running which saw Max Verstappen complete 97 laps for Toro Rosso.
Ferrari’s Antonio Fuoco made his debut, but ended the day in the barrier at Turn 1 when he lost control of the rear of his SF15-T when he put a wheel on the wet grass.
Romain Grosjean was fifth for Lotus, ahead of Red Bull’s Pierre Gasly, Sauber’s Raffaele Marciello, McLaren’s Stoffel Vandoorne and Susie Wolff in the Williams.
| # | Driver | Team | Time | Laps |
| 1 | Pascal Wehrlein | Mercedes | 1:11.005 | 67 |
| 2 | Esteban Ocon | Force India | 1:11.192 | 76 |
| 3 | Max Verstappen | Toro Rosso | 1:11.328 | 97 |
| 4 | Antonio Fuoco | Ferrari | 1:11.331 | 71 |
| 5 | Romain Grosjean | Lotus | 1:11.509 | 45 |
| 6 | Pierre Gasly | Red Bull | 1:11.757 | 80 |
| 7 | Raffaele Marciello | Sauber | 1:11.826 | 53 |
| 8 | Stoffel Vandoorne | McLaren | 1:12.530 | 76 |
| 9 | Susie Wolff | Williams | 1:13.248 | 39 |
