Supercars boss Barclay Nettlefold pictured with Tony Quinn. Image: InSyde Media
The category had appealed a Motorsport Australia stewards decision not to penalise Kai Allen in Perth despite an acknowledged rule breach.
Stewards in Perth had cited mitigating circumstances in issuing no penalty for breaking the 16 psi minimum tyre pressure regulation while on the grid for the Sunday race.
The appeal has been dismissed, with a full judgment to follow within 14 days.
Supercars has seven days from when the full judgement is released to decide whether to take the matter to the FIA International Court of Appeal.
Such an action is thought unlikely, with Supercars instead expected to review its own regulations in the wake of the judgement.
“Supercars acknowledges the authority of the National Court of Appeal and the outcome of this proceeding,” said Supercars CEO Barclay Nettlefold.
“We brought the appeal because we believed that it raised important issues concerning the conduct of Stewards’ hearings and the application of the Rules that warranted consideration by the National Court of Appeal.
“Supercars will consider its position in relation to the future of this matter upon receipt of the written reasons.
“We acknowledge Motorsport Australia and Grove Racing for their professionalism throughout.”
A Supercars statement added: “Supercars is committed to maintaining the integrity of the Championship and the consistent administration of the Rules across all events.
“Supercars looks forward to receiving the Court’s written reasons, which it has indicated it will provide within 14 days.”
Grove Racing also reacted to the news via a statement from team owner Stephen Grove.
“We acknowledge Monday’s ruling and thank the court and its members for their time,” he said.
“The matter is now closed, and our full focus turns to Queensland Raceway and the battle for the Sprint Cup title.
“We thank our crew, partners and fans for their continued support.”