SAKHIR, Bahrain -- Lewis Hamilton set the fastest lap on the first day of Bahrain's two-day in-season test this week, clocking a time 0.626s faster than Ferrari's Antonio Giovinazzi.
In the intense heat of the desert sun, the lap times were some way off Saturday evening's qualifying session but the teams used the session to test and analyse new parts as well as gain a better understanding of Pirelli's new tyres. Hamilton's time was set in the afternoon once the intense track temperatures had dipped and it was quick enough to put a clear gap between Mercedes and rivals Ferrari in the timings. An "electrical disconnection" saw the W08 stop on track early in the session, but it did not take long for the problem to be resolved and the car to return to the track.
Unlike the other nine teams, Ferrari had two cars running on Tuesday as Sebastian Vettel kicked off Pirelli's tyre testing programme in one SF70H and Giovinazzi completed the team's normal test plan in another. A mechanical issue on Vettel's car kept him in the garage for four hours in the middle of the day, resulting in Pirelli asking the other teams if Vettel could continue to test under the floodlights once the normal daytime session had finished. A decision was reached to allow the car to continue on track for an extra three hours until 21:00, extending Vettel's session beyond the 89 laps he had to his name at the chequered flag.
The Red Bull of Daniel Ricciardo was third fastest, 0.991s off Hamilton's pace, but the Australian only completed 45 laps due to an engine issue in the afternoon. After focusing on aero testing and a few short runs in the morning, the Red Bull pulled up on the run down to Turn 1 in the mid-afternoon just as the team was about get stuck into some long runs.
Romain Grosjean was fourth fastest for Haas with 80 laps ahead of the Williams of Felipe Massa, who split the day with teammate Lance Stroll. Nico Hulkenberg was sixth fastest for Renault ahead of Stroll in seventh and Formula 2 driver Sean Gelael, who made his F1 debut in the Toro Rosso. Gelael completed 78 laps despite the car twice stopping on track and causing red flags, with race drivers Daniil Kvyat and Carlos Sainz set to take over on Wednesday. Force India's development driver Alfonso Celis got another test day in the VJM10 and finished the session 10th fastest, 2.581s off the pace of Hamilton. He was quicker than Sauber's Marcus Ericsson and the McLaren-Honda of Oliver Turvey which languished 3.6s off the ultimate pace at the bottom of the timesheets.
After a series of MGU-H problems during the Bahrain Grand Prix weekend, Honda came to the test hoping to try "new ideas" ahead of a full upgrade later in the year. But after just two laps the car hit trouble with a water leak on the Energy Recovery System which forced McLaren to abandon most of the day while the mechanics installed a new power unit and sent the original one back to Honda for further investigation. The car returned to the track in the final hour and Turvey managed 17 laps in total before the chequered flag.
Times at close:
1. Lewis Hamilton, Mercedes, 1:31.358, 97 laps
2. Antonio Giovinazzi, Ferrari, 1:31.984, 93 laps
3. Daniel Ricciardo, Red Bull, 1:32.349, 45 laps
4. Romain Grosjean, Haas, 1:32.452, 87 laps
5. Felipe Massa, Williams, 1:32.509, 56 laps
6. Nico Hulkenberg, Renault, 1:33.624, 74 laps
7. Lance Stroll, Williams, 1:33.729, 35 laps
8. Sean Gelael, Toro Rosso, 1:33.885, 78 laps
9. Sebastian Vettel, Ferrari, 1:33.894, 89 laps+ (Pirelli test car)
10. Alfonso Celis, Force India, 1:33.939, 71 laps
11. Marcus Ericsson, Sauber, 1:34.550, 106 laps
12. Oliver Turvey, McLaren, 1:35.011, 17 laps