Kovalainen impressed with Lotus' pace

The Finn was pleased with his best time, which was 1.3 seconds shy of the fastest, even though he admits it was set on a low-fuel run in the afternoon.

"It was a lower fuel run than we were running all day, but we can go quicker than that if we have to," he told AUTOSPORT.

"It was encouraging. If you look at some of the earlier runs with the medium compound it was pretty good, so we can be quite encouraged about that."

Kovalainen revealed that a problem with the car's exhaust had preventing him from attempting a long run.

"We had some problem with the left-hand side exhaust of the car and the heat. We had to wait a couple of hours to have an extra spare arrive here and it is still a limiting factor for us.

"To do a long run would probably damage it too much. The same place makes a crack and gets bigger. I don't know if we can find a temporary solution over night to get a long run [tomorrow]."

But he says it is too early to judge whether Lotus will be able to challenge the more established teams this season.

"I have a pretty good feeling," he said. "I can only compare to last year and the feeling is totally different. The whole concept of the car is just much better.

"But in terms of the pace, I don't know - no one knows. You talk to the other drivers and everybody was on the hard tyre with heavy fuel!

"You just don't know. I think we're looking pretty good but we don't know what the reality is. We're just guessing at the moment, so it's better not to worry about it too much."