Valtteri Bottas ends first day of young driver testing at Silverstone on top

His time of 1m31.436s, posted in the morning session, was comfortably faster than Marussia's Max Chilton and Rio Haryanto or the HRT of Ma Qing Hua.

The first drops of rain fell at 16:30, bringing in Bottas and Haryanto, but the Finn still went out for a final run before the flag fell.

Bottas concentrated on longer runs during the afternoon, completing a race simulation and taking his tally of laps for the day to 120.

Haryanto finished the day 0.846s slower than Chilton had gone in the morning session in the Marussia, but only completed 19 laps, 15 less than the British driver had done.

His quickest lap (1m37.404s) was done after he had to return to the pits to adjust his brake pedal box, which was not set up to his liking, costing 20 minutes of track time.

Chinese driver Qing Hua went faster in the afternoon on soft tyres, posting his fastest lap of 1m37.829s during a qualifying simulation, although the team reported that he locked his brakes on that lap and lost several tenths of a second.

The rest of the session was spent conducting a mixture of long and short runs on hard and soft tyres and included a spin as Qing Hua activated DRS on the exit of Village.

Today's times:

Pos  Driver              Team                   Time     
 1.  Valtteri Bottas     Williams-Renault       1m31.436s
 2.  Max Chilton         Marussia-Cosworth      1m36.558s + 5.122s
 3.  Rio Haryanto        Marussia-Cosworth      1m37.404s + 5.968s
 4.  Ma Qing Hua         HRT-Cosworth           1m37.829s + 6.393s

All Timing Unofficial