Mercedes confirmed its status as favourite to win the Formula One season-opening Australian Grand Prix by setting the fastest two times in Friday's practice sessions, with Lewis Hamilton edging teammate Nico Rosberg.
Hamilton failed to complete a lap in the opening practice session due to a malfunctioning oil pressure sensor that shut down his engine, but recovered to set a time of one minute 29.625 seconds in the second session around the Albert Park circuit, 0.157 seconds ahead of Rosberg.
"That was quite satisfying," Mercedes team principal Toto Wolff said. "On one lap the pace was good, and on the long run, as well."
He added, however, that Hamilton's early problem meant there is still cause for concern.
"You need to be very careful because it's enough to have a little problem and the race or qualifying could be finished."
Fernando Alonso of Ferrari was fastest in the first session but dropped to third in the second, half a second off Hamilton's time. Kimi Raikkonen was only seventh fastest in his return to the Italian team after suffering some problems, including failing to select first gear when trying a practicestart.
The gaps at the top of the timesheets were reasonably close, which points toward a competitive qualifying session on Saturday and race on Sunday, rather than the Mercedes dominance that many had predicted.
Red Bull's Sebastian Vettel was tipped to struggle in his campaign for a fifth straight drivers' championship due to his team's preseason struggles, but he put in an encouraging performance to finish fourth fastest in practice.