The Australian Touring Car championship has been rumoured to be working on a series based on the 1970s-inspired Formula 5000 category, using the V8 engines currently forming the backbone of Supercars.

New images of a prototype car built by Oscar Fiorinotto emerged on Friday, along with confirmation that Garth Tander, Lee Holdsworth, and Alex Davison have already tested it.

It's a controversial move, given that an independent project known as 'Formula Thunder 5000' has already hit the market.

According to Supercars CEO James Warburton, the Super5000 plan goes back to 2015.

He warned, however, that interest will decide whether or not it becomes a reality.

"Supercars retained the IP rights to a 5000 Series in March 2015 as part of the 2025 vision for sustained growth of the sport and motorsport in this country," Warburton said.

"An increased emphasis on the Dunlop Super2 Series and the introduction of SuperUtes in 2018 are also part of the development of improved and more relevant support categories.

"Now this car has been developed and fully tested the market will ultimately decide."

Two-time Bathurst 1000 winner Tander gave the Super5000 car the thumbs-up.

"The initial impression was 'wow' this is a seriously fast race car and being much lighter than a Supercar with a similar amount of horsepower has plenty of acceleration," Tander said.

"The driveability was fantastic and the traction control means you can tune just how much power you want to the ground so it's not going to snap out on you.

"The car felt comfortable straight away and I had no problems from a safety point of view as it has all of the modern day modern day features including F1 style head protection, which is important in a really fast car.

"It's not every day someone throws you the keys to a 600 plus horsepower open wheeler with big tyres and wings so there will be a pretty long queue to get in one."