Mostert, 32, is stepping back from the Arise Racing Ferrari program with which he won last year’s GT World Challenge Australia title.
He will still attend the SRO Motorsport SpeedSeries events but focus on running his Method Motorsport McLaren GT4 team.
The move was flagged by the Supercars star late last year and comes after a challenging 2024 combining driving and team owner duties.
“I just want to refine the stuff we do with GT4,” Mostert explained to Speedcafe.
“I really enjoy that and the team aspect. I’m going to hang out with the GT4 team at SRO rounds, no driving.
“Last year I found it hard running between GT3 and GT4.
“I was coming back from weekends really cooked. There was too much on my mind. I just want to focus on one thing.”
Mostert co-drove Arise’s lead Ferrari to fourth in Sunday’s 12 Hour after the rapid 296 GT3 proved less fuel efficient than the BMW M4s that cruised to a 1-2 finish.
While largely focusing on the Ferrari effort last weekend, the realities of also have a team in the race hit hard when one of the two McLarens crashed in the second hour.
“I was in the truck, I was talking to my partner at the time, and she said one of my cars had had a moment,” Mostert recounted.
“Once I saw the replay I first of all just wanted to make sure Ryan [Sorenson] was OK. Cars can be fixed but people can’t.
“I saw Ryan [post-race], he’s obviously gutted as any driver is, but like I said to him, it’s better you leave a race track walking than getting a helicopter out.”
While Sorenson escaped injury, the McLaren copped heavy damage.
“It’s going to be a challenge for us. I’ve got two full-time mechanics and they’re always up for the challenge,” Mostert said of fixing the car.
“We’ll strip it, see how bad it is and try and turn it around. We’ve got just under two months before the first race of the series in GT4.
“McLaren has been awesome too; they’ve already said they’ll support us as much as they can to get the car back on track.”
Method Motorsport’s other McLaren Artura ended up winning the GT4 class, which featured just three entries.
Mostert’s decision to sit out the GTWCA season begs the question of whether he’ll be back in a GT3 car for the 2026 Bathurst 12 Hour.
“We’ll see how we go,” said Mostert, who drove one of his McLarens in last year’s 12 Hour before joining the Ferrari program.
“I’m sure Adam (De Borre, engineer) will talk to me and we’ll see what Arise GT is doing. Hopefully someone wants to put me in a Pro car.”
