The CoolDrive-backed Mustang cut its first laps with team co-owner Tim Blanchard behind the wheel this morning, before new signing Hazelwood took over the rest of the day.
According to Hazelwood his starring role in the test came with an unexpected level of pressure given all eyes were on the BRT Ford.
That was combined with it being this first day on the job with the single-car team since his off-season move from Matt Stone Racing.
Given the attention on the car, Hazelwood was thrilled to finish a full day without any major issues.
"It was a weird pressure that I didn't anticipate, to be honest," he told Motorsport.com.
"You know, when it's your first day with the team you always want to do the best job possible. And for me it was the first time I had ever had a brand new chassis at my disposal.
"So you've got the aspect of a brand new car, a new engine, new componentry, a whole new ballgame – and this spotlight on everything because everyone is so keen to see how these new cars perform.
"Fortunately for us it all went really well. I couldn't be happier with how the car ran, it ran faultlessly. We were able to get some good milage and get an understanding of what we're in for for the season ahead."
While the majority of the test was spent on system checks, Hazelwood said he was given some rein to push later in the day.
"We slowly built up to it throughout the day," he said. "The initial part of the day was making sure the car was doing what it should and going through our procedures and checks.
"By the end we put some laps together that were around the 90 per cent mark. There's still some things to refine and get right, but it was a good day. We couldn't be happier."
The test was Hazelwood's first proper milage in Gen3 hardware with his previous experience limited to 30-odd troublesome laps in the Camaro prototype at The Bend last year.
The Winton outing left his wide-eyed in terms of movement, thanks to the dramatic drop in downforce, Hazelwood predicting some wild racing when the season kicks off in Newcastle.
"It's a whole new challenge to understand," he said. "It's a lot different to what I've been used to in Supercars for the last nine years.
"From a driving style, it's something I'll have to think hard about now and get my head around. it's something I'll have to think hard about now and get my head around.
"The cars are brutal, they look cool, they sound good, and they are pretty lively. With the reduction in aero, it's a similar tyre to what we've had in the past, so when you take the aero away, and add more torque, it makes the car very lively through the middle and exit of the corner.
"It's going to put on a show for the fans which is great. I can't wait to see what the racing is like when there's 25 of us all belting into each other in Newcastle. It will be great."
BRT is expected to return to Winton for another test next week before the all-in pre-season test at Sydney Motorsport Park on February 22, and the season opener in Newcastle from March 10-12.
