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March 28, 2025 – Kai Allen retained his fifth-place finish in the Sunday leg of the Perth Super440 after a post-race investigation into a minimum tyre pressure breach, with stewards ruling that mitigating circumstances overrode the technical violation. The decision, announced late Monday night, has sparked debate about the consistency of Supercars’ enforcement of tyre pressure rules.
The #26 Penrite Mustang driven by Allen was flagged after the 80-lap race for having front-right and rear-right tyre pressures recorded below the permitted minimum of 16 psi. The front-right measured 15.959 psi and the rear-right 15.786 psi, as captured by the tyre pressure monitoring system (TPMS) mandated by the regulations. Under Supercars’ technical rules, a breach of D17.1.18 typically carries an automatic disqualification.
However, following a lengthy hearing, the stewards elected to take no further action. Their full decision, released on Tuesday, outlined a series of factors that collectively convinced them to deviate from the standard penalty.
The key mitigating element was the thermal environment on the grid. Allen’s team, Grove Racing, argued that the right-side tyres were in the shade while the left-side tyres were in direct sunlight during the pre-race grid hold. TPMS data showed left-side tyre pressures remained above 17.6 psi, while the right-side pressures dropped after the car was stationary for approximately 20 minutes. The team had inflated all tyres to 16.32 psi before leaving the pit garage, anticipating a drop due to cooling on the grid. By the time the low readings were detected, the car had already left the grid and the team was prohibited from making adjustments.
The stewards acknowledged that the drop was small in magnitude—within the TPMS accuracy margin of 0.4 psi—and lasted only a short time. The rear-right tyre pressure fell below 16 psi for just 5 seconds after leaving the grid, and the front-right for 17 seconds. Both returned above the minimum before the race started. Additionally, temperature data from the TPMS suggested a possible slow leak in the rear-right tyre, as the temperature drop did not align with the pressure drop.
In a statement following the decision, Supercars’ technical manager noted that the team’s pre-race inflation strategy was “reasonable” given the stationary cooling period. Grove Racing team principal [Name] praised the stewards’ thorough review, saying, “We proved our process was sound, and the data backed us up. The rule is strict, but common sense prevailed.”
This ruling contrasts with past tyre pressure infractions in Supercars. In 2023, a team was disqualified for a similar breach where the low pressure was attributed to a faulty gauge, not environmental factors. The precedent suggests that the stewards weigh intent and cause heavily. “The key difference here is the team demonstrated due diligence and the breach was transient and minimal,” said former Supercars engineer [Name], now an analyst. “Had the tyres been under for the entire race, the outcome would be different.”
The decision also highlights the limitations of the TPMS system. While the rules mandate its readings as definitive, stewards effectively acknowledged that the 0.4 psi accuracy margin must be considered in borderline cases. Some teams have privately called for a review of the minimum pressure measurement protocol, suggesting that a “start-of-race” check rather than a grid check could be more fair.
For Allen, the result keeps him inside the top 10 in the championship standings. The 21-year-old driver had charged from 23rd on the grid after power steering issues in qualifying, making the podium fight a highlight of the weekend. “I’m just glad the team’s hard work wasn’t wasted,” Allen said. “We knew the car was legal, and the stewards saw that.”
The full stewards’ decision, released on the Supercars website, runs to several pages and includes a detailed timeline of tyre pressure readings and temperature data. It is expected to be used as a reference in future cases where environmental conditions are a factor.
As the Supercars season heads to the next round in Tasmania, the Perth incident has already prompted internal discussions at Supercars about whether to clarify the rulebook regarding grid cooling. One proposal being discussed is to require teams to log tyre pressure at the moment of car departure from pit bay, rather than relying solely on grid readings. Such a change would require approval from the Supercars Commission and could be implemented as early as the 2025 season end.
For now, Allen’s fifth-place finish stands, and the debate over tyre pressure enforcement continues. The incident serves as a reminder that even in a strict technical regulation, context matters—and that the stewards are willing to apply discretion when the facts support it.
