Webber keeps Red Bull on top in Britain

With Silverstone baked in sunshine - a track temperature of 43 degrees throughout the 90 minutes - and the grandstands impressively packed for a Friday, the Red Bulls dominated once they switched onto the softer tyre and started setting quick times.

Webber's best effort lifted him a full second clear of the other teams, with Sebastian Vettel nearly seven tenths down in the second RB6 following a high-speed spin at Stowe early on. The Australian's session ended 15 minutes early when he was forced to pit with an electrical problem, but his 1m31.234s was easily good enough to stand.

Ferrari elected to stick with the F-duct after both drivers tested with and without it, and once the soft tyres were bolted on Fernando Alonso split the Red Bulls, just under four tenths behind Webber.

Felipe Massa finished the session fourth quickest, despite flying off the road at Becketts and Village during practice. The two Mercedes of Nico Rosberg and Michael Schumacher were fifth and sixth - the only other cars within 1.5 seconds of the benchmark time.

Vitaly Petrov was seventh for Renault, ahead of Lewis Hamilton - sporting a new Grenada flag helmet design - who continued to struggle to keep his McLaren on the road, going off twice in the Becketts complex.

Adrian Sutil and Rubens Barrichello completed the top 10, with Jenson Button only 13th.

Lotus suffered more reliability problems during the session, with Jarno Trulli forced into the pits after just three laps with gearbox trouble and Heikki Kovalainen stopping at Stowe with a power steering failure.

Sakon Yamamoto seemed to be struggling physically at the wheel of the second HRT car by the end of practice. He finished the session in 23rd place, 1.3 seconds slower than team-mate Karun Chandhok.

Pos  Driver         Team                   Time              Laps
 1.  Webber         Red Bull-Renault       1:31.234            15
 2.  Alonso         Ferrari                1:31.626  + 0.392   26
 3.  Vettel         Red Bull-Renault       1:31.875  + 0.641   24
 4.  Massa          Ferrari                1:32.099  + 0.865   25
 5.  Rosberg        Mercedes               1:32.166  + 0.932   29
 6.  Schumacher     Mercedes               1:32.660  + 1.426   27
 7.  Petrov         Renault                1:32.745  + 1.511   28
 8.  Hamilton       McLaren-Mercedes       1:32.757  + 1.523   22
 9.  Sutil          Force India-Mercedes   1:32.787  + 1.553   27
10.  Barrichello    Williams-Cosworth      1:32.967  + 1.733   32
11.  Kubica         Renault                1:33.019  + 1.785   30
12.  Hulkenberg     Williams-Cosworth      1:33.164  + 1.930   28
13.  Button         McLaren-Mercedes       1:33.200  + 1.966   24
14.  Kobayashi      Sauber-Ferrari         1:33.402  + 2.168   23
15.  Liuzzi         Force India-Mercedes   1:33.728  + 2.494   27
16.  Buemi          Toro Rosso-Ferrari     1:33.836  + 2.602   36
17.  de la Rosa     Sauber-Ferrari         1:34.051  + 2.817   29
18.  Alguersuari    Toro Rosso-Ferrari     1:34.643  + 3.409   36
19.  Kovalainen     Lotus-Cosworth         1:35.465  + 4.231   25
20.  di Grassi      Virgin-Cosworth        1:36.237  + 5.003   24
21.  Glock          Virgin-Cosworth        1:36.553  + 5.319   21
22.  Chandhok       HRT-Cosworth           1:37.019  + 5.785   27
23.  Yamamoto       HRT-Cosworth           1:38.303  + 7.069   32
24.  Trulli         Lotus-Cosworth         1:42.901  + 11.667  3

All Timing Unofficial