Kimi Raikkonen put a revived McLaren back on top of the timesheets in practice for the team's home British Grand Prix.
The young Finn, overall runner-up last year but little more than an also-ran in an uncompetitive car for the first half of this season, lapped in one minute 18.655 seconds on Friday, a mere 0.005 of a second quicker than Sauber's Italian Giancarlo Fisichella.
Fisichella's day was bittersweet, his car finding its pace only after the engine was changed in the morning -- a move imposing a 10 place penalty on the starting grid after Saturday's qualifying.
Ferrari's world champion Michael Schumacher, dominant winner of nine of the season's 10 races and seeking his 80th career victory on Sunday, was third fastest.
Raikkonen's British team mate David Coulthard, twice a winner at Silverstone, was fourth while compatriot and home favourite Jenson Button in a BAR was fifth.
Ferrari's Rubens Barrichello had earlier fired up his challenge for a second successive win in Britain with the fastest time in the day's first practice.
The Brazilian, without a victory so far this season, won from pole position with a lap record time in 2003 and is eager to repeat the feat after finishing runner-up six times in the last 10 races.
Williams looked strong in the first session, with Colombian Juan Pablo Montoya third and Spanish stand-in Marc Gene fourth quickest in his second race in a row as a replacement for injured Ralf Schumacher.
Germany's Timo Glock crashed with eight minutes remaining in the second session when his Jordan lost a rear wheel. The test driver emerged from the car unscathed.
