Andretti takes aim at Penske in Supercars

In the end, the motivation behind US motorsport great Michael Andretti's landmark decision to buy into battling Supercars outfit Walkinshaw Racing was simple.

"Any chance you get to beat Roger Penske, you take it," Andretti said.

Andretti will renew his rivalry with legendary IndyCar team owner Penske in Australia next year after Walkinshaw Racing (WR) dropped their bombshell on Thursday night.

Five months before the touring cars are unleashed for another year, WR is set to become a powerhouse again after IndyCar outfit Andretti Autosport and McLaren Formula One chief Zak Brown's United Autosports confirmed they would buy into the once mighty Holden team from 2018.

From January 1 the team will be known as Walkinshaw Andretti Autosport, pending Supercars approval.

WR team boss Ryan Walkinshaw and Andretti will be equal stakeholders, with Brown holding a minority share.

Quite simply, this is a game changer.

Andretti is part of American racing royalty.

And Brown? He was the man touted to take over from Formula One boss Bernie Ecclestone.

All of a sudden, the forgotten former factory-backed Walkinshaw outfit that once boasted Peter Brock, Craig Lowndes and Mark Skaife has all the resources in the world to return to Supercars' summit.

Walkinshaw described it as a "beginning of a new era" in Supercars.

Andretti saw it as another chance to take down his nemesis Penske.

"He's the benchmark in the sport," Andretti said of his long-time foe.

"If you can beat him, you can beat anybody.

"So I am very excited to go head to head with him again."

WR will be hoping to replicate Penske's success since he entered Supercars in 2015.

He took a major share in Ford legends Dick Johnson Racing to form DJR Team Penske -- a partnership that is now dominating the Supercars championship.

Their drivers Scott McLaughlin and Fabian Coulthard are first and third respectively heading into this weekend's Bathurst 1000.

Andretti -- the son of motorsport great Mario -- is also one of the most successful drivers in American open wheel history.

Since retiring from driving, Andretti began his own IndyCar team, which features his son Marco, as well as a team in the FIA Formula E Championship and the Global Rallycross Championship.

The American great is track side ahead of Sunday's Great Race at Mount Panorama.

It is a monumental coup for WR whose future appeared in doubt when they lost their 2017 Holden factory backing after 26 years in a shock move.

Their fortunes haven't changed this year -- their drivers Scott Pye and James Courtney are 18th and 19th respectively in the standings.

WR -- once the Supercars pace setters -- are a distant sixth in the Supercars teams' championship.

"Today is the beginning of a new era. We are still firmly focused on the job at hand for 2017, but are eagerly looking forward to 2018," Walkinshaw said.

"This combination of international expertise is a pivotal step in accelerating our development, getting us where we need to be."