Erebus Motorsport rookie duo Will Brown and Brodie Kostecki completed an "encouraging" first test as full-time Supercars drivers.
Brown and Kostecki form an all-new line-up for Erebus in 2021 following the departures of David Reynolds and Anton De Pasquale.
The team has also undergone engineering changes, with Tom Moore and George Commins to engineer Brown and Kostecki respectively.
On Wednesday, the pair recorded approximately 80 laps each at Winton Motor Raceway as part of a rookie test, with team boss Barry Ryan pleased with the "positive" hit-out.
The drivers ran a special testing livery, which Erebus revealed prior to the test on Wednesday.
The black scheme will also be present at the official pre-season test at Winton on February 16.
Brown said the early laps in a car set-up to his liking will help ahead of the upcoming pre-season test.
"I guess a lot of the other guys have done so many laps over their lifetime, so it's great for us to get extra laps that's for sure," the 22-year-old said.
"We've got new engineers stepping up, new drivers and everything there, and I think we actually improved the cars a lot.
"I actually feel quite confident. I really liked the way the team worked and the way we got the car better throughout the day.
"I'm really happy and think we can press forward for the next test day."
Kostecki felt "more confident" in a car tuned to his liking versus his co-driver role at Bathurst.
"Simple things like getting the seat set-up for myself instead of being a co-driver. Just a few things to do with set-up direction, more to my driving style," he explained.
"It was a good day for my confidence.
"I think this test was really important for us just with George coming in and Tom stepping up to the plate on Will's car, just getting a general understanding of how the new team dynamic would work.
"Everyone gelled together really fast. Everyone seemed to know what everyone was doing.
"All the mechanics just jumped in whenever there was a change. Just very simple communication.
"Everything was done very efficiently and effectively. I can't complain really."
The rookie duo will return for the official test day with other Victorian teams before the season-opening Repco Mt Panorama 500. Tickets are on sale now.