Just one week ahead of the Sonsio Grand Prix at the iconic Indianapolis Motor Speedway (road course), INDYCAR has announced a key update to its tire usage rules that promises to shake up race strategies and deliver even more excitement for fans.
Under the revised regulations, teams will now be required to use two sets of alternate tires and two sets of primary tires during the race – one additional set of each compound compared to previous requirements. The new rule is designed to push teams and drivers toward more aggressive, on-the-limit racing while adding a strategic layer to an already competitive field.
“INDYCAR is continually looking into ways to improve an already extraordinary on-track product,” said INDYCAR President J. Douglas Boles. “Firestone is a terrific partner, and their higher degradation alternate tire has given strategists plenty to think about on road and street circuits this year. We expect this update will challenge teams and drivers even more.”
Importantly, there is no requirement that these sets be new (sticker) tires, offering teams flexibility in how they manage their tire inventory across the weekend. The rule mandating that two laps must be completed on each tire compound – with one of those laps starting under green flag conditions – remains in effect (Rule 15.3.3.2.3.).
This move comes in conjunction with INDYCAR’s broader strategy to enhance race weekends. The series has confirmed that the standard tire allocation of five primary and five alternate sets per road/street course weekend (introduced earlier this season) was designed with this type of format in mind. For the IMS road course – the only two-day road and street circuit event on the 2025 schedule – the allocation will remain five primary and four alternate sets.
What This Means for Race Day
With tire degradation playing a more prominent role, fans can expect more pit stops, varied strategies, and dramatic shifts in performance across stints. Whether teams go for a bold alternate-heavy approach or manage their primaries for long-run consistency, this update guarantees unpredictable and thrilling action on track.
In addition, Practice 2 has been shortened from a 45-minute guaranteed green flag period to 35 minutes, aiming to increase urgency and ensure more meaningful on-track activity in the lead-up to qualifying and race day.
INDYCAR has stated that it will review the results of these changes following the event and assess whether this format could be adopted at future races.
written by Philipp Kraus / Media Credit: Penske Entertainment
