Mark Webber says the Red Bull team's off-season testing has done a good job of preparing him and Vettel to get to grips with the new rule changes in F1.
Yesterday he recorded fifth-fastest lap time in their second day of practice, while team-mate Vettel was fourth.
McLaren's Button and Hamilton were first and second respectively, and Hamilton poked fun at the Red Bull team saying they were "just a drinks company".
Webber quipped back that they were a very fast one.
Today the drivers practice again at Albert Park, then the qualifying session takes place to establish grid positions.
Can Button make it three consecutive wins at Melbourne, or will Webber finally achieve a home win?