Rain-affected opening practices in Melbourne did nothing to dampen Caterham's quiet optimism ahead of the new Formula One season.

The Hingham marque saw Heikki Kovalainen in among Williams and Toro Rosso during the morning session, while the Finn was even more impressive during a more soggy and ultimately slower second session.

Vitaly Petrov maintained a reasonable gap to his team-mate on his Caterham debut at a grand prix weekend, one which McLaren's morning running caught the eye as Jenson Button and Lewis Hamilton produced the fastest times of the day, while Michael Schumacher topped the afternoon charts.

'The car felt good from the first proper run this morning and we found that the baseline we had set over the winter carried over exactly as we had planned into today's practice sessions,' said Kovalainen.

'It's a shame the conditions meant that we couldn't test the tyres more but that's the same for everyone, so the main thing was that we had a good balance all day, and kept improving the setup in both sessions.

'It's also good to see that the new spec front wing that we ran both this morning and this afternoon is giving more grip overall, so that's another positive step forward and puts us in good shape for tomorrow.'

Russian star Petrov only replaced Jarno Trulli after the first winter test in Jerez, but is starting to feel comfortble in his new surroundings.

'The main things for me today is that I feel very comfortable with the team,' said Petrov. 'We're quickly building up a good relationship between me and the engineers and the mechanics, so as that keeps growing we'll be able to get more out of the car and keep finding the pace that we know this car has.'

Norwich-born chief technical officer Mike Gascoyne said: 'It does look like the midfield group is going to be very tightly packed and I hope we can have a dry qualifying session to find out just how competitive we can be.'

Chief executive Riad Asmat added: 'We obviously can't tell too much from the times but it is encouraging to see that we are lapping consistently in the sort of times we have been aiming to.

'Now the focus turns to Saturday when we will hopefully have more dry running and find out just where all the hard work over the winter has put us.'