Nico Rosberg topped the opening practice session for the British Grand Prix despite suffering a gearbox problem after just five laps.
Rosberg was 0.070s faster than Mercedes team-mate Lewis Hamilton after rejoining the track in the final five minutes and improving his lap time on his last two attempts. The No.6 Mercedes pulled to the side of the track after experiencing a loss of hydraulic pressure with just 17 minutes on the clock, but the team managed to rectify the issue and send Rosberg back out for a flurry of laps at the end, two of which were fast enough to usurp Hamilton at the top of the leader board.
Hamilton's morning was not completely without drama; he spun 15 minutes into the session when he ran slightly wide exiting Stowe. However, he managed to complete 14 laps more than Rosberg over the course of the 90 minutes, which will be far more valuable to the world champion than the bragging rights of finishing the first Friday session on top.
Max Verstappen was third fastest but a whopping 1.256s down on the lead Mercedes. The Toro Rosso driver was, however, 0.058s faster than Kimi Raikkonen in the highest-placed Ferrari, with Verstappen's team-mate Carlos Sainz in fourth. Raikkonen suffered a loss of power from his MGU-H unit at one stage, but was back on track to improve his lap time in the final minutes. Sebastian Vettel had to settle for sixth place in the second Ferrari ahead of the Red Bulls of Daniel Ricciardo and Daniil Kvyat.
Nico Hulkenberg was ninth fastest in the updated Force India ahead of Felipe Massa in tenth place in the Williams. Susie Wolff drove Valtteri Bottas' Williams in the opening session and managed the 13th fastest time ahead of fellow FP1 substitutes Jolyon Palmer in the Lotus and Raffaele Marciello in the Sauber.
McLaren's session got off to a slow start with a leak on Jenson Button's car after its installation lap while Fernando Alonso was preserving mileage on an old Honda engine, which replaced an updated unit that was damaged during his accident in Austria. Button was just 0.12s quicker than Will Stevens in the fastest Manor as both drivers got their hands on updated machinery for the first time. The McLaren features the new nose first used by Fernando Alonso in Austria, plus various other updates to supplement it, while the Manor has new front and rear wings as well as tighter sidepods and improvements to the floor.