German Grand Prix, 23-25 July, Hockenheim
Coverage: Live on BBC One, Red Button, BBC Sport website and Radio 5 live
Full details of practice, qualifying and Sunday's race
Hamilton hammers wall in first practice
By Sarah Holt
BBC Sport at Hockenheim
McLaren driver Jenson Button admits the pace of Ferrari and Red Bull has him worried ahead of the German Grand Prix.
The Briton put in 36 laps but ended the session 1.5 seconds off Ferrari's pace-setter Fernando Alonso and a second off the slower Red Bull, Mark Webber.
"The Red Bulls and Ferrari look fast, faster than we expected," he said. "I don't know if we'll be as quick."
Button's team-mate Lewis Hamilton was "upset" with himself, meanwhile, after a crash curtailed his first practice.
The 2008 champion spun at Turn Three an hour into the opening session and was sent careering into the barrier, damaging all four corners of his car.
It meant he had to sit out the rest of the first practice session, and all but 12 minutes of the hour-and-a-half session.
Hamilton said: "It's been quite an interesting day for me.
"I damaged the car quite heavily this morning but the guys have done an incredible job.
"I was a little bit upset with myself as you see the guys work so hard during the week then you do only a few laps and you total the car.
"It was very very slippery but it was a relief when I came back and they explained to me how it occurred - I shifted, hit the limiter and then I spun the wheels, had an oversteer moment which I tried to correct and didn't correct it well enough and it put me off onto the grass.
"So it meant a huge, huge amount of work for the guys but they're just phenomenal and they did an awesome job."
But he remained optimistic of his chances ahead of Sunday's race, adding: "At least I've got something to work on now and have a good feeling where the car is."
We can have a good race here and with a bit more set-up work I think the car can be competitive
Button was more mindful of McLaren's leading rivals, however, after both Red Bull and Ferrari showed excellent pace around a damp Hockenheim.
The 2009 champion complained of rear instability in his first practice as the McLarens - like all the teams - had trouble on the slippery wet surface, and although he finished that session third fastest, he could not keep up with the leading teams in the afternoon.
"The Red Bulls and Ferraris look surprisingly quick - but then they always do on Fridays," said the 30-year-old.
He was, though, happy enough with the car's upgraded blown rear diffuser, which had to be taken off the cars after the first day's practice at the British Grand Prix after it caused instability and overheating.
"I don't have a negative feeling with the upgrades at all," he said. "I feel we have better traction and balance.
"Then again we have nothing to compare it against at the moment. So we'll see on the data.
"We can have a good race here and with a bit more set-up work I think the car can be competitive, but I don't know if it will be as quick as the Ferraris or the Bulls as they've set a blistering pace this afternoon.
"We don't have a very good set-up in the wet. We changed the car over the break and this afternoon it felt a lot better than this morning.
"There are things we have to do to make the car better."
But he warned against reading too much into his pace in the afternoon, explaining: "We got on with our programme today but Lewis had his problem in the morning and so I had quite a busy afternoon making sure we got through our run programme.
"This afternoon we ran on lower fuel and higher fuel. Then we put fuel in the car and did long runs. And then we went back out and did a front wing comparison at the end which was useful.
"I didn't really get much set up work done so Saturday is important. Hopefully it will be dry and we can do some session work."
Highlights - German GP first practice