McLaren F1 star Alonso came close to testing Australian Supercar

McLaren executive director Zak Brown was running his 2011 Holden Racing Team Commodore at Aragon late last year on the same day that Alonso was testing the United Autosports Ligier LMP2 car, leading to an idea for the double F1 world champion to have a go in the Bathurst 1000-winning Supercar.

But the plan came to a grinding halt late in the day when the car ran dry with Filipe Albuquerque at the wheel.

"It was one of these 'if we had time at the end of the day to do a lap, I'd love to do a lap' [situations] - and we ran out of petrol," said Brown.

"Actually, Filipe was in the car when it ran out going down the back straight.

"If we would've had time, [Alonso] would've had a go.

"Fernando was in a very strict mindset. It's kind of 'I've looked at it, I've looked around it, now let me go do my job and at the end of the day when I'm out of that mode, if we've got time, I'll go have a play'.

"But we ran out of time, and gas. He'd like it."

Brown added that he could see Alonso actually racing a Supercar at some point in the future, providing he felt he could be competitive.

When asked if there was anything Alonso would not try his hand at, Brown said: "Anything that he doesn't think he can win in, which unfortunately has been our [McLaren] car the last few years - but hopefully that'll change.

"He's the biggest racer I've ever seen. He loves all different types of racing - he's fascinated by it. But whatever he does, he wants to do it very seriously.

"So he would never come and do something that he didn't think he could be competitive in."

Brown picks Bathurst over Japanese GP

Brown is involved in Supercars thanks to his co-ownership of the Walkinshaw Andretti United team.

Supercars' showpiece Bathurst 1000 clashes with F1's Japanese Grand Prix again in 2018, and Brown has already decided that he will skip Suzuka that weekend.

"I'm going to do Bathurst. I'll miss the Japanese Grand Prix, I'll go to Bathurst," he confirmed.

"It's obviously the biggest [Supercars] race, a lot of our commercial partners will be there. To me, Bathurst, Le Mans, Indy 500, Monaco, it's of that calibre.

"I've always wanted to go to Bathurst and I think McLaren will survive without me for the weekend.

"They're very comfortable with my racing involvements. McLaren always comes first, but on a race weekend, my role is a leadership role, a commercial role. I'm not helping them make faster pitstops."

Brown added that he and WAU team co-owner Michael Andretti are aiming to be at "three to four" Supercars races each during 2018.