"It is just everyone getting used to it and understanding what is different and where it is different. I don't think it is affecting things too much - it has made it a little bit smoother in places and that is always a good thing."
The weather was grey and overcast but the track remained dry throughout the session. There is rain forecast later in the day and into tomorrow, which could make life challenging for the drivers.
Coulthard wasn't too worried if it rained in the later practice session on Friday.
"It doesn't matter to me - at the end of the day it is the same for everyone. If it is going to be wet tomorrow then maybe it would be nice to get a bit of rain now but it is not the be all and end all," he said.
Reigning series champ Shane van Gisbergen posted only the 19th fastest time although he remained in the pits during the back end of the session having early set times comparable with the leading drivers.
Jack Perkins was the first driver to feel the bite of the challenging Pukekohe Park Raceway circuit. The experience racer was a late replacement in the Lucas Dumbrell Motorsport team for Alex Rullo this weekend and he made an auspicious start by running off the track at the final corner and scraping his Holden along the pit straight wall. He managed to limp the car back to the pits but took no further part in the session.
Teammate Aaren Russell brought out a red flag with 11 minutes remaining in the session when he went off at turn one and got caught in the sand trap.
A second 40-minute practice session runs just after 3pm.
