Red Bull HRT team principal Roland Dane says the Supercars' fleet of Commodores must accept their "performance disadvantage" after falling further behind in the title fight at Phillip Island.
The sport's dominant team find themselves in an uncomfortable position after four meets - on the outer, and unsure how to improve.
Ford's domination of the 2019 championship has been almost total. They've won nine of the 10 races and the top three drivers in the championship are steering Mustangs.
Scott McLaughlin leads with 1058 points, DJR Team Penske teammate Fabian Coulthard is second with 934 points and Chaz Mostert has improved to third with 815.
Dane's former champion Shane van Gisbergen is fourth, but the Kiwi - like his teammate Jamie Whincup - wasn't a factor in either race on the Island.
"We're trying to walk a tightrope in the performance window," Dane said.
"We're trying to find something that, to be honest, fundamentally isn't there. All the Holden teams are. We're doing all sorts of things trying to find it.
"You see it with all the Holden teams, with Erebus, with Walkinshaw as well ... we are at a performance disadvantage. We have to accept that."
Whincup, who was second in the championship before arriving at Symmons Plains last weekend, has slumped to ninth in the standings after a 25th-placed finish and a DNF in back-to-back meets.
Whincup said on Saturday he couldn't "remember a car with so little grip than that, I'd have to go back 15 years".
"We are not performing as well as we would like," he said.
"We have certainly dropped off quite substantially from last season. There's no secret, we are not hiding behind it and not saying it's bad luck.
"You can call it a slump, but we will fight our way out of it."
If there was a shining light for the Commodores, it was a first podium for Anton de Pasquale in Sunday's race.
