Kamui Kobayashi has warned not to read anything into his test-topping lap time at Barcelona on Friday.

13563 - Headline time 'not a real result' - Kobayashi

The Sauber driver clocked the fastest time of the week during the morning session with a 1:22.312 as his team completed a qualifying simulation just before the lunch break. However, he is not getting carried away.

"It's better than nothing, better than last for sure," he said. "I don't think this is a real result and I know more than anybody about this situation. I don't think the McLaren and Red Bull are so slow."

Kobayashi set his best time on soft tyres despite doing a similar short run on super-soft tyres. He said this was due to him having a better understanding of the soft compound.

"When I did the fast time on super-softs maybe I made a mistake with warm-up," he admitted. "I know soft compounds better than super-softs so I can build up the warm-up and everything, but super-softs I have no idea how to use it, so I could not use them well. But I think the grip is more with super-softs."

Last year's Sauber struggled with tyre warm-up in qualifying but was able to go for long distances in the race. This year Kobayashi said there was no problem with getting heat into the tyres but that the degradation was much higher across the range of new Pirelli tyres.

"This year tyre warm-up seems fine, very good," he said. "I think everybody had a good lap time, a fast, flowing lap and then on the second lap they [the tyres] never came back. Even cooling them down cannot recover the tyre grip. I think in the race there is definitely a bigger drop [in degradation] for all the tyres, so hopefully there will be more pit stops."

He said long runs were now the focus for the final test, but admitted Sauber would not be bringing a huge amount of updates to Barcelona next week.

"It's not easy to find new parts in one week but we have to find more set-up work, more long runs with heavy fuel - I think this will be key for Melbourne," he added. "Of course, if we can have new parts it will be great but I think one week is not enough."