The Red Bull drivers were cautiously satisfied with their form in free practice in Melbourne, as the champion team started 2011 with a one-two in the opening session.
Morning pacesetter Mark Webber was then fifth in the afternoon, one place behind team-mate Sebastian Vettel.
"It was an exciting start to the season, as there's always a lot going on in Melbourne," said Vettel.
"We were able to complete a lot of laps today, but the weather has been a bit difficult. It starts raining, but then goes dry again, which doesn't make it that easy to test different things.
"Despite that, I think we got a good idea as to where we are compared to our competitors. All in all I think we can be pleased, it seems we are not too bad, but we have to wait and see."
Webber suggested that Red Bull did not have a clear advantage over the field and had "work to do" but was also generally upbeat about his day.
"We had some Melbourne showers at the end of P2, which are always pretty tricky round here, but in general it was a pretty good day for us," he said.
"We've still got some work to do; there are some quick guys out there.
"It was good to finally try the tyres out on this circuit and I had a go with everything new on the car.
"McLaren look quick, but with Ferrari you can never tell, as they always run a bit more fuel on a Friday."