Mostert reveals 'tricky' decision on champion's #1

Chaz Mostert has confirmed he will defend his Repco Supercars Championship with the #1 on his Walkinshaw Andretti United Toyota Supra.

Mostert claimed his maiden drivers’ championship in a thrilling conclusion to the season at the bp Adelaide Grand Final on Sunday.

The #25 Mobil 1 Optus Ford had the #1 applied after the race for the team celebrations, before the car was on display at Monday’s Gala Awards.

Mostert has run the #25 since joining WAU in 2020, racing the number to Bathurst victory in 2021 before clinching his maiden title this year.

In Supercars, the #1 is reserved for the champion, and has been used by the last two winners, Brodie Kostecki and Will Brown.

Kostecki returned the #1 to the grid for the first time since 2018, after Scott McLaughlin and Shane van Gisbergen opted to retain their #17 and #97 respectively.

It will return again in 2026 — and this time, it will be on a Supra. Mostert, though, agonised over the decision, given how close he has grown to the #25.

“It’s been tricky. I watched Gizzy [van Gisbergen] come up here and he’s so attached to his number,” Mostert said on Monday night.

“I am a little bit too because #25 has been pretty remarkable for me. I’ve been lucky enough to represent some amazing numbers in Supercars.

“But it would be pretty unfitting if we didn’t run #1 and #2 at Walkinshaw Andretti United, so we’ll run the #1 next year. I’m pretty excited about that.”

The Walkinshaw squad claimed its first drivers’ title since Mark Skaife in 2002, but has run the #1 for Garth Tander (2008) and James Courtney (2011) after they both joined the team as champions.

The new Supra makes its competitive debut at the 2026 season opener in Sydney on February 20-22. All tickets for Friday will be free, opening up the sport to new audiences.