Andre Heimgartner has produced the fastest practice time at slippery Reid Park Circuit in Townsville ahead of Saturday's qualifying and first race.
The Brad Jones Racing driver set the two quickest times in Friday's afternoon second practice session after championship leader Shane Van Gisbergen went fastest in practice one.
Registering podiums in Western Australia, Winton and a strong performance in the previous Darwin leg, Heimgartner said familiarity with his setup had aided his form.
"It (the car) seems to be carrying around a pretty familiar theme since Perth which has worked for us and seems to be working," he said.
But when asked about track conditions and how the harder compound tyres were holding up on the circuit, Heimgartner was blunt.
"The difference between the two sessions was pretty significant," he told reporters.
"I think a lot of people changed their car to suit the end of practice one and probably regretted that at the start of practice two.
"We're going to see a similar evolution tomorrow morning, different temperature, all that sort of stuff."
Both practice sessions were difficult for drivers as they navigated less grip across the 2.8 kilometre hybrid circuit with super soft tyres only available for the weekend's two races.
Heimgartner said the harder compounds will mean less overtaking over the two 250 kilometre races with errors expected as degradation kicks in.
Cameron Waters, who was second quickest on Friday, agreed.
"I don't think we're going to see a lot of passing on the hard tyres," Waters said.
"It's pretty sketchy on the brake zones, so to ask a bit more from it, it's not going to give it to you."
Saturday's V8 Supercars qualifying begins at 9.50am before a top ten shootout for pole.
Race 19 of the season will start at 2.50pm.
V8 Supercars Championship standings:
1. Shane Van Gisbergen (Red Bull Ampol Racing) 1581 pts
2. Anton De Pasquale (Shell V-Power Racing) 1367 pts
3. Cameron Waters (Monster Energy Racing) 1293 pts
4. Will Davison (Shell V-Power Racing) 1287 pts
5. David Reynolds (Penrite Racing) 1111 pts.
