Kobayashi plays down loss of mileage

The Japanese driver spent just over five hours in the pits after the early failure today, but said he would rather get reliability issues out of the way in testing.

"We had some trouble with fuel, but it's better to know that now than next week," he said. "I did about 20 laps, and we collected some data as well.

"If we don't have any problem tomorrow we can finish our whole programme. I'm not worried. And if we have no problem in the car all week in Jerez and then we go to a race and have big trouble it will be a big mess, you know? It's better to do some troubleshooting now."

Although Kobayashi missed out on a lot of dry running on the first rain-free test day of the week, he said Saturday's promising forecast should give Sauber plenty of chance to make up for lost time.

"Tomorrow is supposed to be good weather as well, so we can continue with our programme," he said. "At the moment it's okay, I'm not really worried or anything. And my pace, I would say, is acceptable at the moment in terms of lap time. I'm not worried. It's okay. If we have problems now, we should be okay for the races."

But he emphasised that being sidelined for so long today made it even harder to estimate where Sauber stood compared to its rivals.

"We have no idea. Today we only did 20 laps, you know?" Kobayashi said. "We are not really in the right situation to decide where we are.

"Of course we collected some data, but we didn't do a lot of work today - things like set-up work. We had the fuel system problem for most of the session. But we are quite confident."