Fan Info - INDYCAR 101 - Rulebook - Chapter 15: Tires

Download Updated Rulebook: 2019 NTT IndyCar Series Rulebook (Full)

IMPORTANT: The rulebook content below was released to all parties on March 1, 2019, and should be considered UNOFFICIAL. No in-season amendments or bulletins are reflected in the below copy. Please refer to the above PDF link for the updated rulebook.


15.1. General

15.1.1. Only Tires supplied by Firestone and approved by INDYCAR may be used. Each Tire must be used in its specified location. Schrader valves must be used as supplied by Firestone. Valve caps must be used during all on-Track activity and must provide an air-tight seal.

15.1.2. Tires are assigned to a specific Entrant. Tires may not be sold, traded or otherwise reassigned, given or transferred to any other Entrant.

15.1.3. Tires may not be changed on a Car once the Car is in its position in the Starting Lineup on the Grid without INDYCAR approval.

15.1.4. Tire warmers are not allowed.

15.1.5. No substance may be applied to the Tires.

15.1.6. Only nitrogen or compressed air may be used to inflate Tires.

15.1.7. An Entrant may only possess the following Tires: tow Tires, set-up Tires, rig testing Tires, and two (2) sets of wet Tires.

15.1.8. All other Tires must be returned to Firestone immediately following an on-Track Event. Unreturned Tires are subtracted from the Entrant’s allotment at the following Event.

15.2. Tire Allotments

15.2.1. Each Entry is permitted the following:

2018 Tire Allocation
Event Venue Primary Alternate

Rookie Driver

St. Petersburg 7 4 1
COTA 7 4 1
Barber 7 4 1
Long Beach 7 4 1
Indianapolis RC 7 4 1
Indianapolis 500® 36 0 0
Detroit 9 4 1
Texas 14 0 0
Road America 8 4 1
Toronto 7 4 1
Iowa 10 0 0
Mid-Ohio 7 4 1
Pocono 12 0 0
Gateway 11 0 0
Portland 7 4 1
Laguna Seca 7 4 1
COTA Open Test 8 0 1
Indianapolis 500® Open Test 4 0 0
Indianapolis 500® ROP 3 0 0
Indianapolis 500® Refresher 2 0 0
Indianapolis 500® Fast Nine (*) 2 0 0
Laguna Seca Open Test 4 0 1
(*) Each Entrant qualifying for the Fast Nine will be allotted two set of tires for use Sunday, May 19. One set to be used only during the Fast Nine morning practice session. The second set to be used during Fast Nine Qualifications.

15.2.2. Single Event Race Weekends: A maximum of five (5) sets of wet Tires [including two (2) sets transported by the Entrant].

15.2.3. Double-Header Race Location: A maximum of seven (7) sets of wet Tires [including two (2) sets transported by the Entrant].

15.3. Road Course / Street Course Tires

15.3.1. Rookie Drivers Rookie Drivers may purchase one (1) additional set of Tires for use during practice session one (1). If purchased, the additional set of Tires is returned at the completion of practice session one (1).

15.3.2. Practice/Returning Tires At the completion of practice session one (1), Entrants must return one (1) set of either primary or alternate Tires. At the completion of practice session two (2), Entrants must return one (1) set of Tires and they must be the opposite compound (primary/alternative) of Tires returned at the completion of practice session one (1).

15.3.3. Race Tires Within thirty (30) minutes of the completion of the practice/Qualifications session prior to the Race, an Entrant must notify INDYCAR via IM to the tire declaration account the Tire Compound it will use for the Race start. Failure of an Entrant to submit the required notice will result in INDYCAR assigning the Entrant the Tire Compound chosen by fewer Entrants. A Car must complete two (2) laps on each Tire Compound. Single Races: One (1) set of new (sticker) alternate Tires and one (1) set of primary Tires must be used. Double-Header Races: One (1) set of alternate Tires and one (1) set of primary Tires must be used. One (1) lap must begin once the Green Flag has been displayed to the Race Leader as decided by INDYCAR. The second (2nd) lap may be completed in Pit Lane, even if the Car’s Pit Box is prior the Start Finish Line. Any Car failing to comply with this Rule shall receive a minimum one (1) lap penalty. If a Car has Tire damage due to contact, the two (2) lap requirement for that Tire Compound will be considered fulfilled. This Rule does not apply if INDYCAR declares a wet start or wet condition and/or three (3) or more Cars from different Entrants use wet Tires after the start of the Race.

15.3.4. Wet Tires Practice: Wet Tires may only be used when wet conditions exist. Qualifications: Wet Tires may only be used when wet conditions exist. Race: If INDYCAR declares a wet start, Cars must complete one (1) official lap on wet Tires which must start under a Green Flag. The lap may be completed in Pit Lane even if the Car is pitted before the Start/Finish Line.

15.4. Oval Event Tires

15.4.1. Entrants may start a Race on any of its allotted Tires.

15.5. Replacement Tires

15.5.1. The Event replacement tire allotment is eight (8) tires for the Racing Season: Primary: 1 tire (max) per Race Location Alternate: 1 tire (max) per Race Location (4 for season) A replacement tire will only be allotted when the tire being replaced is returned to the Tire Mounting Area. Allotment tires requested during Qualifications must be approved by INDYCAR prior to the tire being mounted. Allotment tires are only available during INDYCAR-sanctioned Races.

15.5.2. Unused replacement Tires returned to the Tire mounting area will not be credited back to the Entrant’s annual allotment.