Supercars has taken the extraordinary step of appealing one of its own stewards' decisions, lodging a notice of intention to appeal the ruling that let Kai Allen keep fifth place at the Perth Super440 despite a proven minimum tyre pressure breach.
Allen charged from 23rd on the grid to fifth in Sunday's 80-lap race after a power steering problem wrecked his qualifying. Afterwards, Supercars' own technical department reported that the front-right and rear-right tyres on his #26 Penrite Racing Ford Mustang had been recorded below the mandated 16psi minimum - 15.959psi and 15.786psi respectively.
Technical breaches are normally open-and-shut cases that end in disqualification. After a lengthy Sunday night hearing involving Grove Racing chief executive Brenton Grove and head of performance Al McVean, the Motorsport Australia stewards upheld the allegation but applied no penalty, citing mitigating circumstances.
Grove Racing executive chairman Stephen Grove made clear he did not see the appeal coming.
"We are surprised to learn that Supercars has chosen to appeal the outcome of the independent Motorsport Australia Stewards' hearing regarding the #26 Penrite Racing Ford Mustang in Race 25," Grove said in a statement.
"To our knowledge, this is the first time Supercars has appealed a decision arising from a Motorsport Australia Stewards' hearing to overturn the decision and have a sanction imposed on one of its teams.
"We question the process moving forward and look to seek clarity around when Supercars will and won't involve themselves in matters and outcomes that have already been determined by the sport's governing body."
Rival drivers have not hidden their anger. Brodie Kostecki, the 2023 champion, argued on his Lucky Dogs podcast that the margin was anything but trivial once the tyres came up to temperature.
"That is quite a big difference," Kostecki said. "As the temperature rises, that pressure actually multiplies with the temperature. The ambient temperature for the day was 27 degrees. If you put that tyre to 100 degrees, what it operates at during the race, that pressure then multiplies.
"That's 1.7psi at running pressure, 1.6psi, which is probably a 0.3-second advantage, 0.2-second advantage. This is quite a big performance advantage."
Will Brown, the 2024 champion, said the non-penalty effectively rewrites how every team will set tyres from now on.
"A lot of teams are probably starting around 16.5 to 16.6psi to make sure that when they go out of the pits, roll around and sit on the grid for 30 minutes, they cannot go below the minimum pressure," Brown said.
"I don't understand - and neither can our team or probably any team down pit lane - how Grove Racing got away with that. As me and Andrew discussed on Sunday night before we flew out, let's just set our tyres at 16psi. Now the precedent is set that if they drop to 15.7, it's okay."
The stewards' published reasoning explains the leniency. Grove inflated all four tyres to 16.32psi leaving the garage, the pressures read roughly 17psi on arrival at the grid, and the right-hand side sat in shade while the left-hand tyres baked in the sun above 17.6psi. The tyre pressure monitoring system carries an acknowledged 0.4psi accuracy variance, stops producing data once the car is stationary, and teams are forbidden from touching pressures on the grid. Both tyres were back above 16psi within five and 17 seconds of the formation lap starting.
Writing for V8 Sleuth, Shane Rogers likened the move to a prosecutor appealing a sentence it considers too light, and argued Supercars faces a bind either way: minimum pressures are a safety rule, so if the decision stands, the category must instead rewrite the regulations - a higher minimum with a stated tolerance, or rules covering the formation lap and grid top-ups.
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*Originally published on [Motorsports Global](https://motorsports.global/article/supercars-appeals-kai-allen-non-penalty-in-unprecedented-move). Visit for full coverage.*