2009 Australian Grand Prix

Entrants

The season opens with 20 drivers in ten teams. The new Brawn GP team makes its debut, with Ross Brawn’s buyout of Honda confirmed only three weeks before the race. Jenson Button and Rubens Barrichello carry over from Honda. Sébastien Buemi makes his Formula One debut at Toro Rosso, the first Swiss driver in Formula One since Jean-Denis Délétraz in 1995. He replaces Sebastian Vettel, who moves to Red Bull Racing in place of the retired David Coulthard. McLaren and Renault threaten to boycott the opener over a financial dispute with the FIA, but both teams arrive in Melbourne.

Several teams protest the legality of the double-diffuser designs on the Brawn GP, Williams, and Toyota cars before the race begins. The stewards declare the cars legal; the protesting teams appeal, with a hearing set for after the Malaysian Grand Prix.

Weather

Race day conditions are clear with an air temperature of 25 °C.

Practice

Williams set the pace in all three free practice sessions, with Nico Rosberg and Kazuki Nakajima going first and second in FP1, separated by five-hundredths of a second. Rosberg was again fastest in FP2, with Barrichello second and Jarno Trulli’s Toyota third. Rosberg completed the sweep of sessions in FP3. Sebastian Vettel’s FP1 was disrupted by a hydraulic failure that ended his session early, restricting him to four laps.