The silver cars were among the pacesetters throughout practice, but it was Heikki Kovalainen rather than local hero Lewis Hamilton - who had a notable grassy moment - leading the way. "We shouldn't get carried away with being fastest on Friday afternoon, but we've got a good basis for Sunday," Kovalainen said.
Mark Webber, who lost time with an electrical problem in the morning, and David Coulthard were both in the top four in the afternoon session. Don't expect them to maintain those sorts of positions throughout the weekend, though -- in the media release, the pair respectively described the day as "not bad" and "normal".
Both cars were inside the top ten in the afternoon, but Kazuki Nakajima lost time after he spun and was collected by the barriers on the run to Bridge corner.
Sebastian Vettel, despite hardly knowing the Silverstone layout, was a top-seven contender throughout the opening day of practice, consistently a lot quicker than teammate Sebastien Bourdais.
Jenson Button, wearing a special helmet livery designed by a fan this weekend, and teammate Rubens Barrichello, looked more competitive in the afternoon, when they were in the top ten. Morning mileage was limited because of concerns about a suspension failure on Barrichello's car.
Felipe Massa's fastest morning time was not bettered even after he slid on Fernando Alonso's spilt oil and crashed heavily at Stowe, nor throughout the entire afternoon session, when he returned to the track in a repaired car and was eighth. Kimi Raikkonen was 12th in the afternoon. "I had a bit of a struggle to find the best settings on the car," he said.
The media release described Friday as a "quiet start" for BMW-Sauber, after Robert Kubica and Nick Heidfeld finished the afternoon outside the top ten.
Surely one of Jarno Trulli's worst days in formula one; slow in the morning, slowest in the afternoon, and heavily in the Stowe corner barriers after his rear wing fell off. "I was taken to the medical centre for a routine check but I am fine and cleared to return to the cockpit tomorrow," he said. Timo Glock, whose similar rear wing was reverted to an older spec after Trulli's crash, seemed quicker than his teammate, before his afternoon was interrupted with a clutch problem.
The oil from Fernando Alonso's blown engine pitched Massa into the barriers in the morning, and the Spaniard was just 15th quickest in the afternoon. Nelson Piquet was one or two tenths slower.
Giancarlo Fisichella started his day getting the all-clear from doctors to race this weekend following his heavy testing crash last week. He ended up 16th, with Adrian Sutil a couple of tenths behind.