The German summer weather was disappointing on the first day of free practice before the Formula One Grand Prix in Hockenheim. While in the first session there was only light rain to contend with, the second session in the afternoon turned out to be completely wet. In the morning Sauber F1 Team driver Kamui Kobayashi was busy with aerodynamic measurements, while his team mate, Sergio Perez, also did some aero testing as well as work with a new hard tyre compound from Pirelli. In the afternoon both drivers worked on a rain set up for the Sauber C31-Ferrari, as it might also be wet for Saturday's qualifying, while the race on Sunday is expected to be held in dry conditions.

Sergio Perez: "Of course we were hoping for more dry running today, but it is good we now have some experience with both the intermediate and full wet tyres, because we might need them for qualifying tomorrow. I really hope we can put in a strong qualifying performance so we can make the most of our chances in the race. Regarding the new hard tyres we were using in the morning, I found it difficult to warm them up but overall to me they seemed to be alright."

Kamui Kobayashi: "I was struggling a lot in the wet and I had zero grip. I suppose there was something wrong with my car and we will check that now. Tomorrow is another day and I'm positive we can be strong here."

Giampaolo Dall'Ara, Head of Track Engineering: "It was another Friday of fighting with the weather. We tried to maximise our learning, and apparently we have to find the best possible compromise because the weather forecast suggests it will be wet for qualifying but dry for the race. In the morning we were able to work on measurements related to aero parts. For the afternoon we had a revised programme due to the rain. Overall it is obviously very difficult to make a judgement on today's performance."

Check out our Friday gallery, here.