Shane van Gisbergen, the current championship leader, was fastest in practice on the first day of the Castrol Gold Coast 600 in Surfers Paradise.
The Kiwi driver from Red Bull Racing emerged from the melee on top, after he used a new set of tyres in the frantic final five minutes to set a practice lap record of 1m10.420s.
Compatriot Scott McLaughlin did his best to chase down van Gisbergen, finishing just 0.1sec behind after an excellent stint.
"The car feels amazing. Straight out of the truck, we haven't really changed anything. I'm pretty confident for tomorrow," McLaughlin said.
His Volvo teammate James Moffat was third fastest a further 0.2s behind while Chaz Mostert jumped 20 spots on his final run to end up in fourth in the Prodrive Ford.
Of the other Kiwi main drivers Andre Heimgartner was 13th fastest, Fabian Coulthard was 15th, and Super Black Racing's Chris Pither 16th.
Van Gisbergen's Red Bull teammate Jamie Whincup, who failed in his appeal on his penalty at Bathurst which would have unseated the Kiwi from top spot in the championship, was fifth fastest just ahead of the Holden of Dave Reynolds and New Zealand co-driver Craig Baird.
Tomorrow is qualifying and the first 300km race.