A hydraulic leak required a full power-unit change.
The day kicked off with Jenson conducting some aerodynamic tests, which meant he only completed a single timed lap.
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. The time required to complete the change unfortunately meant that our running for the day was over before lunchtime.
Today’s unofficial testing times
1 Felipe Massa - Williams (1m23.500s / 103 laps)
2 Marcus Ericsson - Sauber (1m24.276s / 122 laps)
3 Lewis Hamilton - Mercedes (1m24.881s / 48 laps)
4 Daniil Kvyat - Red Bull (1m25.947s / 75 laps)
5 Romain Grosjean - Lotus (1m26.177s / 75 laps)
6 Kimi Raikkonen - Ferrari (1m26.327s / 80 laps)
7 Carlos Sainz Jnr - Toro Rosso (1m26.962s / 86 laps)
8 Jenson Button - McLaren-Honda (1m31.479s / 7 laps)
What’s next: Jenson resumes testing duties again tomorrow.