As we’re approaching the end of the 2015 F1 Pre-Season tests, teams are starting to get a better idea of how they might perform during races once the regular season starts in Melbourne, Australia in two weeks time.

Teams are also starting to feel more pressure, especially those who are either under-performing or just performing badly – and to be honest, we’re only talking about McLaren-Honda here, as they discovered a hydraulic leak today that ended Jenson Button’s run after only 7 laps on the track.

“After just seven laps, Jenson noted a vibration and brought the car back to the pits, where we discovered a hydraulic leak that required a full power-unit change,” read the official McLaren statement. “The time required to complete the change unfortunately meant that our running for the day was over before lunchtime.”

Doing much better were Williams, who actually dominated the day thanks to Felipe Massa’s amazing 1:23.500s lap time, almost a second clear of Sauber‘s Marcus Ericsson and Mercedes‘ Lewis Hamilton – who only completed 48 laps.

Toro Rosso came out with a new front nose on their STR10 car, which Carlos Sainz Jr drove for 86 laps, without managing to impress with his speed.

Testing resumes on Friday when Force India will finally debut their new VJM08 racer with Nico Hulkenberg at the wheel.

Unofficial Day 1 (Round 2) times from Barcelona

1. Felipe Massa, Williams, 1:23.500s, 103 laps
2. Marcus Ericsson, Sauber, 1:24.276s, 122 laps
3. Lewis Hamilton, Mercedes, 1:24.881s, 48 laps
4. Daniil Kvyat, Red Bull, 1:25.947s, 75 laps
5. Romain Grosjean, Lotus, 1:26.177s, 75 laps
6. Kimi Raikkonen, Ferrari, 1:26.327s, 80 laps
7. Carlos Sainz Jr, Toro Rosso, 1:26.962s, 86 laps
8. Jenson Button, McLaren, 1:31.479s, 7 laps

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