WAU kicked off a three-day test with the Bathurst 1000 wildcard entry at the Victorian circuit today, Rossi doing the lion's share of the early running thanks to co-driver James Hinchcliffe's late arrival from The States.

It wasn't just his first look at the circuit, but also his first taste of a proper touring car, his closest experience being an Acura DPi prototype.

While well out if his comfort zone, the Indy 500 winner was surprised by how quickly he adapted to the 650-horsepower Holden.

He reckons he was just four-tenths behind lead WAU driver James Courtney earlier this afternoon, despite not having the latest aero updates on the car.

"It’s like an IndyCar test, so we only have the times from our own team," he said.

"I think we’re six-tenths to a second off [the ultimate pace] but we don’t have the supersoft qualifying tyre here and that’s worth a second, the team are saying.

"Courtney is the quick guy and right now we’re 0.45s off him. It’s okay.

"And it’s not as hard to get used to as I thought, or as I’d heard. But it’s going to be hard to find the last second for qualifying, for sure.

"It’s very unique technique stuff. So getting down to a generally good lap time was a lot more straightforward than I was expecting, considering the closest thing I’d ever raced was a DPi car in IMSA!

"I mean, I’ve never raced a touring car or GT car."

Expanding on the driving style required for the cars, Rossi said the braking technique was proving the most difficult to master.

The balance, however, he says is surprisingly similar to an IndyCar.

"Funnily enough, the balance is like an IndyCar in that the predominant trait is understeer and as you try and tune it out, it most affects corner entry," he said.

"So that’s something I’m pretty used to!

"The hardest thing is the braking, because it’s so understeer heavy, you have to trail-brake a lot and you’re super-prone to the inside wheel locking.

"And you have no idea when you are locked up – you don’t feel it, you don’t see it, you don’t hear it. All of a sudden you’re going straight and it’s a surprise.

"That’s the hardest thing, so I think all my time lost is on the brakes. You don’t have downforce, so you can’t have a big brake spike like in a formula car, so you actually brake in a way that you have the higher pressure at the end of the braking zone, when there’s less demand.

"It’s very strange – kind of backward. Everything’s back to front, we’re in Australia!

"You turn the brake bias in the opposite direction. There’s just a lot of little things that feel a bit weird."

Sitting on the right-side of the car is something Rossi says hasn't been an issue.

"That was another thing that I expected would take a while to get used to, along with how to use the track width and the curbs – but it’s not even a problem," he said.

"It’s funny how your brain can adapt. A non-issue."

Despite the promising run, Rossi said he's not getting ahead of himself in terms of expectations.

"I can get within half a second of my teammate here but Winton is a pretty elementary track," he said.

"Comparing myself at Bathurst to someone who’s been racing these cars and that track for 12 years could be a different story!

"I’d be pretty pumped to get through to the Top 10 shootout, but I don’t know how realistic that is, to be honest.

"We’re going to be getting quite a bit of assistance from [parity] because of how the Fords have had it so far this year. And the [parity] is all aimed to kind of help at Bathurst, so in theory we could be pretty good… but I’m not tempting fate.

"Actually, I don’t even have the [aero] updates on my car – the team simply don’t have the parts yet."

Having only arrived in the country this morning, Hinchliffe has now completed a seat fitting in the car, and is set to turn his first laps this afternoon.

WAU is running all three of its cars at Winton today, but will continue with just the wildcard entry for the next two days.