The call for the first day of practice ahead of the European Formula One Grand Prix at the street circuit in Valencia was to find the best downforce level for the Sauber C31-Ferrari, which has to suit for qualifying as well as for the race, and to understand how the tyres - the medium and the soft compounds are provided by Pirelli - work on this particular track. It was a busy day for the Sauber F1 Team. In the morning several test items also had to be run, while in the afternoon Kamui Kobayashi's car had an hydraulic problem and Sergio Perez wasn't happy with the balance of his car. There is still some work to do.

Kamui Kobayashi: "For me it was quite okay today, except for an hydraulic problem which prevented me from doing long runs in the afternoon. In the morning we had a couple of test items. This worked fine and was the reason why I didn't do performance runs in the first session. Despite the fact that there had not been too much time for set up work, the car was good when we fitted the soft tyres. Tyre management will be the key here and this depends not only on the driving, but also on the car's set up. For the race it is important to get everything right in this regard so that the tyres don't drop off too quickly, but tomorrow first we have to focus on qualifying. The grid position here is more important than on other tracks because overtaking is really difficult."

Sergio Perez: "For me it was a rather difficult day because I wasn't happy with the balance of my car. On low fuel I struggled a lot, while it was better on a high fuel load. Kamui and I had different programmes for today and we now have a lot of data to be analysed and compared. I think we probably have found something today what could help us for tomorrow."

Giampaolo Dall'Ara, Head of Track Engineering: "We are not really happy with how the day went. We expected to have a lot of homework to do, because this track is not the easiest for our car. We dedicated the morning to quite a lot of aero work with both cars, which was positive because we were able to gather a lot of data. In the afternoon we concentrated mainly on race preparation with some tyre work and some more validations on the aero side. With Kamui we were able to find a good balance and get him happy with the car, however, he lost a lot of track time because of what looks to be an hydraulic leak which we weren't able to fix during the session. We will have to analyse this very carefully. Sergio was not happy with the balance of the car, so we have a lot of work to do there as well. Overall, it was a mixed day."

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