“The car was good straight away. Even on the warm-up tyres we use to warm the brakes up it was really good,” said McLaughlin.
“I’m struggling a little bit with the Turn 1 bumps, I might have to look at some previous footage to see if I’ll change anything, so we’ll work on that.
“We need to run through some race cambers and things as well, so we’ll see how we go.”
Team-mate Fabian Coulthard sat second for a long period before the Shell Fords were split by David Reynolds' Erebus Holden with 12 minutes remaining.
Brad Jones Racing’s Tim Slade then moved to second with just seconds remaining, falling 0.05s short of McLaughlin.
Defending champion Shane van Gisbergen spent the bulk of the session outside the top 10 before rising to fifth ahead of early pace-setter Rick Kelly.
Chaz Mostert, Will Davison, Michael Caruso and Nick Percat completed the top 10, with the BJR Holden receiving a fresh engine following an issue in the additional driver session.
Todd Hazelwood set the pace in Tim Blanchard's BJR Holden during the earlier session but was 22nd in his first run aboard the Matt Stone wildcard entry.
“Tim’s car overall was very well balanced and feels a little bit softer compared to my car. The rate of the roll is a little bit different as well,” said Hazelwood of the two cars.
“We’ll try and take the positives out of that and develop it into this car, but we’ve got a pretty strong base car out of our test day and have good data to work with, so we’ll see what we can come up with.”
Jack Le Brocq was the top wildcard in the session, putting his MW Motorsport Nissan 15th.
Those struggling included Mark Winterbottom, who managed just 26th – 1.5s adrift of team-mate Mostert.
“The car is horrible, there’s no hiding behind it,” said Winterbottom.
“I don’t know why it’s so bad, but thankfully it’s Practice 1 and not Race 1 because with two sets of tyres I’ve never had a car handle like that before.
“It’s just got no front-end. When you turn in the front just folds and I’m just running out of road because the corner ends at some stage and I’m still trying to turn.”
A second 45 minute session will conclude today’s running later this afternoon.