Mark Webber fastest in free practice ahead of Mercedes . Mercedes driver edges out Red Bulls of Mark Webber and Rosberg . Home hope Lewis Hamilton three best at Silverstone . Rosberg won Silverstone earlier this season .
Nico Rosberg fastest in free practice ahead of the British Grand Prix . Mercedes driver edges out Red Bulls of Mark Webber and Sebastian Vettel . Home hope Lewis Hamilton fifth best at Silverstone . Rosberg won the Monaco Grand Prix earlier this season .