Bottas quickest in Silverstone testing
Valtteri Bottas was quickest during the young driver test at Silverstone
Williams' emerging reserve driver Valtteri Bottas wrapped up the young driver test at Silverstone on another positive note.
Williams and Marussia were the only teams to take to the shorter international circuit on Friday as HRT returned home after all three marques had used the grand prix track on Thursday.
Bottas was again quickest, completing 170 laps as he assisted the team in aerodynamic work, with the 22-year-old Finn's best run in 48.963secs.
For Marussia, both Britain's Max Chilton and Rio Haryanto from Indonesia completed enough laps and kilometres to gain their superlicence required to move up to Formula One.
Chilton, 21, finished 0.969secs adrift of the more-experienced Bottas, while 19-year-old Haryanto was 1.442secs down.